CARDIOLOGY Flashcards
Location of sinus node
Superior aspect of the crista terminalis
Ridge of muscle where the posterior smooth atrial wall derived from the sinus venosus meets the trabeculated anterior portion of the right atrium
Crista terminalis
Sinus rate increases spontaneously at rest or out of proportion to physiologic stress or exertion
Inappropriate sinus tachycardia
Symptomatic sinus tachycardia that occurs with postural change from supine to standing position
Postural orthostatic tachycardia syndrome (POTS)
Postural orthostatic tachycardia syndrome (POTS) is defined as:
Rate increases by 30 bpm or to >120 bpm within 10 min of standing, with no hypotension
Factors that plays prominent roles in the development of coronary atherosclerosis in women than in men (4)
Inflammation
Obesity
Type 2 DM
Metabolic syndrome
Exercise ECG has a higher diagnostic accuracy in the prediction of epicardial obstruction in women than in men. True or false.
False. Lower.
Mechanism of myocardial ischemia
Imbalance between the heart’s oxygen supply and demand
NYHA Class I definition
No limitation of physical activity.
No symptoms with ordinary exertion
NYHA Class II definition
Slight limitation of physical activity
Ordinary activity causes symptoms
NYHA Class III definition
Marked limitation of physical activity
Less than ordinary activity causes symptoms
Asymptomatic at rest
NYHA Class IV definition
Inability to carry out any physical activity without discomfort
Symptoms at rest
Pitfalls in cardiovascular medicine (3):
- Failure by the noncardiologist to recognize important cardiac manifestations of systemic illnesses
- Failure by the cardiologist to recognize underlying systemic disorders in patient with heart disease
- Overreliance on and overutilization of laboratory tests, particularly invasive techniques, for the evaluation of cardiovascular system
Asymptomatic or mildly symptomatic patients with VHD that is anatomically severe should be evaluated periodically, every _______.
6-12 months
Dysplastic pulmonic valves due to mutation in chromosome 12
Noonan syndrome
Mutation in the PTPN1 gene
Noonan syndrome
RV dysfunction from afterload mismatch occurs earlier in the course of PS. True or false.
True. RV adapts less well to this type of hemodynamic burden
Definition of severe PS
Peak systolic gradient across the pulmonic valve of >50 mmHg
Definition of moderate PS
Peak systolic gradient across the pulmonic valve of 30-50 mmHg
Higher pressures needed to fill a noncompliant, hypertrophied RV in pulmonic stenosis causes this wave change
RA a wave elevates (Prominent a wave may be seen in the jugular venous pulse)
This wave change/characteristic signifies functional TR from RV and annular dilation in pulmonic stenosis
Prominent RA v wave
Crescendo-decrescedo, mid-systolic, heard best in the left 2nd ICS
Pulmonic stenosis
The only right-sided murmur that decreases in intensity with inspiration
The ejection sound/ click that precede the murmur of pulmonic stenosis. The PS murmur increase in intensity during inspiration
Percutaneous pulmonic balloon valvotomy indications (2):
Symptomatic patients with a domed valve and a peak gradient > 50 mmHg (or mean gradient > 30 mmHg)
Asymptomatic patients with with a peak gradient > 60 mmHg (or mean gradient > 40 mmHg)
(used only in less than moderate PS)
High-pitched, decrescendo diastolic murmur, along the left sternal border
Graham Steell murmur
4 other terms for MVP
a. Systolic click-murmur syndrome
b. Barlow’s syndrome
c. Floppy-valve syndrome
d. Billowing mitral leaflet syndrome
Most common abnormality leading to primary MR
MVP
One of the causes of MVP is the reduction of production of what type of collagen?
III
MVP is a frequent finding in patients with heritable disorders of connective tissue, such as: (3)
a. Marfan syndrome
b. Osteogenesis imperfecta
c. Ehlers-Danlos syndrome
Which mitral leaflet is mostly affected in MVP
Posterior mitral leaflet
MVP is more common in what population (gender and age group)?
a. Women
b. Ages of 15 and 30 years
In older (>50 years) patients, MVP is more common in what gender?
Men
Mid- or late-(nonejection) systolic click is seen in what valvular abnormality?
MVP
Systolic click followed by a high-pitched, mid-late systolic crescendo–decrescendo murmur is a feature of
MVP
Leaflet involved in MVP when the radiation of the murmur is to the base of the heart
Posterior leaflet prolapse (Jet of MR is directed anteriorly)
Leaflet involved in MVP when the radiation of the murmur is to the axilla and the back
Anterior leaflet prolapse (Jet of MR is directed posteriorly)
Earlier with standing, MVP murmur is increased or decreased?
Increased
During the train phase of the Valsalva maneuver, MVP murmur is increased or decreased?
Increased
During any intervention that decreases LV volume (preload), MVP murmur is increased or decreased?
Increased
During squatting, MVP murmur is increased or decreased?
Decreased
During isometric exercises, MVP murmur is increased or decreased?
Decreased
Indications for MVP repair (5):
a. Symptomatic severe MR
b. LV systolic dysfunction
c. Pulmonary artery hypertension
d. Recent onset AF
e. Flail mitral leaflet
Can be considered for treatment of symptomatic patients at high surgical risk with severe primary MR due to MVP
Transcatheter edge-to-edge repair
Mortality of NYHA FC IV
30-70%
Mortality of NYHA FC IV
5-10%
Compensatory mechanisms become activated in the presence of cardiac injury and/or LV dysfunction allowing patients to sustain and modulate LV function for a period of months to years. What are the 2 known mechanisms
(1) activation of the renin-angiotensin-aldosterone system (RAAS) and the adrenergic nervous system (which are responsible, respectively, for maintaining cardiac output through increased retention of salt and water )
(2) increased myocardial contractility
Refers to the changes in LV mass, volume, and shape and the composition of the heart that occur after cardiac injury and/or abnormal hemodynamic loading conditions
Ventricular remodeling
The cardinal symptoms of HF (2)
fatigue and shortness of breath
The most important mechanism of cardiac dyspnea is pulmonary congestion with accumulation of interstitial or intra-alveolar fluid, which activates ___________, which in turn stimulate the rapid, shallow breathing characteristic of cardiac dyspnea
juxtacapillary J receptors
T or F: Dyspnea may become less frequent with the onset of right ventricular (RV) failure and tricuspid regurgitation
True
It results from redistribution of fluid from the splanchnic circulation and lower extremities into the central circulation during recumbency, with a resultant increase in pulmonary capillary pressure.
Orthopnea
Nocturnal cough is a common manifestation of this process and a frequently overlooked symptom of HF
acute episodes of severe shortness of breath and coughing that generally occur at night and awaken the patient from sleep, usually 1–3 h after the patient retires
paroxysmal nocturnal dyspnea
with persistent coughing and wheezing
even after they have assumed the upright position
Periodic respiration or cyclic respiration that is present in 40% of patients with advanced HF and usually is associated with low cardiac output
Cheyne-Stokes respiration
Cheyne-Stokes respiration is caused by (2)
an increased sensitivity of the respiratory center to arterial Pco2 and a lengthy circulatory time
Electrical diastole is slowing of what action potential phase
slow diastolic depolarization (phase 4)
Phase of action potential upstroke of nodal cells
Phase 0
Phase 0 of nodal cells is mediated by
calcium rather than Na
L-type Ca current
Mechanisms causing bradycardia (2)
- Failure of impulse initiation due to depressed automaticity
- Failure in impulse conduction that is may be due to exit block or fibrosis
The only reliable therapy for symptomatic bradycardia in the absence of extrinsic and reversible etiologies
Permanent pacemaker
SA nodal artery arises from either of these 2
- RCA – 55-60%
* LCx – 40-45%
Membrane potential of SA node
-40 to -60 mV
T or F. SA node has slow phase 0 and rapid phase 4
True
Heritable form of sinus node disease caused by autosomal dominant mutations in the If subunit gene HCN4 on chromosome 15
Tachycardia-bradycardia variant of sick sinus syndrome 2
Heritable form of sinus node disease caused by autosomal recessive mutations in cardiac Na channel gene, SCN5A on chromosome 3
Sick sinus syndrome 1
Heritable form of sinus node disease that presents as ophthalmoplegia, pigmentary degeneration of the retina, and cardiomyopathy
Kearns-Sayre syndrome
Failure of the SA node to discharge, producing a pause without P waves visible on ECG up to 3 s
Sinus pauses
Intermittent failure of conduction from the SA node
Sinus exit block
intermittent conduction from the SA node and a regularly irregular atrial rhythm characterized by intermittent absence of P waves
2nd degree SA block
Progressive prolongation of SA node conduction with intermittent failure of the impulses originating in the SA node to conduct to the surrounding atrial tissue
2nd degree SA block type 1
SA block with no change in SA node conduction before the pause
2nd degree SA block type 2
SA block characterized by no P waves on the ECG
Complete or 3rd degree SA block
Most common tachycardia in the tachycardia-bradycardia in SSS
Atrial fibrillation
Also, atrial flutter and atrial tachycardia
Inability to increase the HR in response to exercise or other stress appropriately
Chronotropic incompetence
Chronotropic incompetence is defined as failure to reach ___ of predicted maximal heart rate at peak exercise or failure to achieve a HR ____ with exercise or a maximal heart rate with exercise less than ___ standard deviations below that of an age-matched control population
85%
> 100 bpm
2 SD
Diagnostic test for carotid sinus hypersensitivity
ANS testing
Normal intrinsic heart rate in ANS testing? And measured after giving these 2 medications (with dose)
117.2-(0.53 x age) bpm
After administration of 0.2 mg/kg propranolol and 0.04 mg/kg atropine
Low IHR in ANS testing is indicative of
SA disease
Longest pause after cessation of overdrive pacing of the RA near the SA node in the electrophysiologic testing
Sinus node recovery time (SNRT)
In EPS testing, ½ the difference between the intrinsic sinus cycle length and a noncompensatory pause after a premature atrial stimulus
Sinoatrial conduction time (SACT)
Drug that shorten SNRT and may improve SA node dysfunction
Digitalis
1st letter in the nomenclature of permanent pacemakers is the
chamber(s) that is paced
2nd letter in the nomenclature of permanent pacemakers is the
chamber(s) in which sensing occurs
3rd letter in the nomenclature of permanent pacemakers is the
response to a sensed event
- O – none
- I – inhibition
- T – triggered
- D – inhibition plus triggered
4th letter in the nomenclature of permanent pacemakers is the
programmability or rate response
R – rate responsive
5th letter in the nomenclature of permanent pacemakers is the
existence of anti-tachycardia functions if present
- O – none
- P – anti-tachycardia pacing
- S – shock
- D – pace + shock
Most commonly programmed modes of implanted single-chamber pacemakers
VVIR
Most commonly programmed modes of implanted dual-chamber pacemakers
DDDR
Permanent pacemakers are most commonly implanted via
subclavian-SVC venous system
Rotation of the pacemaker pulse generator in its subcutaneous pocket can wrap the leads around the generator and produce dislodgement with failure to sense or pace the heart causing
Twiddler’s syndrome
Rare complication in small-sized and light weight pacemakers
Achilles heel of permanent pacing systems
Transvenous leads
Constellations of signs and symptoms due to interruption and failure to restore AV synchrony by the pacing modes
Pacemaker syndrome
Neck pulsation, fatigue, palpitations, cough, condusion, exertional dyspnea, dizziness, syncope, elevation in JVP, canon A waves, and signs and symptoms of CHF
This will minimize the sequelae of pacemaker syndrome
Maintenance of AV synchrony
Class I indications for pacemaker implantation in SA node dysfunction (4)
- SA node dysfunction with symptomatic bradycardia or sinus pause
- Symptomatic SA node dysfunction as a result of essential long-term drug therapy with no acceptable alternatives
- Symptomatic chronotropic incompetence
- Atrial fibrillation with bradycardia and pauses >5 s
Class IIa indications for pacemaker implantation in SA node dysfunction (3)
- SA node dysfunction with heart rates <40 beats/min without a clear and consistent relationship between bradycardia and symptoms
- SA node dysfunction with heart rates <40 beats/min on an essential long- term drug therapy with no acceptable alternatives, without a clear and consistent relationship between bradycardia and symptoms
- Syncope of unknown origin when major abnormalities of SA node dysfunction are discovered or provoked by electrophysiologic testing
Class IIb indication for pacemaker implantation in SA node dysfunction
Mildly symptomatic patients with waking chronic heart rates <40 beats/min
Class III indications for pacemaker implantation in SA node dysfunction (3)
- SA node dysfunction in asymptomatic patients, even those with heart rates <40 beats/min
- SA node dysfunction in which symptoms suggestive of bradycardia are not associated with a slow heart rate
- SA node dysfunction with symptomatic bradycardia due to nonessential drug therapy
Initiating event for cardiac contraction
Depolarization of the heart
Atrial repolarization waveforms in ECG
ST-Ta
Phase of rapid upstroke of action potential
Phase 0
Onset of QRS
Plateau phase of action potential
Phase 2
Isoelectric ST segment corresponds to what phase of action potential
Phase 2
Phase of active repolarization
Phase 3
T wave
Amiodarone effect on QT interval
increase the QT interval
Hypocalcemia effect on QT interval
increase the QT interval
Hypercalcemia effect on QT interval
shorten QT
Digoxin effect on QT interval
shorten QT
Activation of the atria from an ectopic pacemaker in the lower part of either atrium or in the AV junction region causes these p waves
Retrograde P waves
Negative in II, positive in aVR
ECG marker (in terms of U wave) of increased susceptibility to torsades de pointes
Very prominent U waves
RA overload is defined as P wave of
≥2.5 mm
P-pulmonale
Most common arrhythmia in pulmonary embolism
Sinus tachycardia
ECG abnormality typical of pulmonary embolism
S1Q3T3
- Prominent S wave in Lead I
- Q wave in Lead III
- T wave inversion in Lead III
LVH Sokolow lyon and Cornell criteria
- S in V1 + R in V5 or V6 = > 35 mm
* R in aVL + S in V3 > 20 mm in women or >28 mm in men
ECG findings that is a major noninvasive marker of increased risk of cardiovascular morbidity and mortality rates, including sudden cardiac death
ECG evidence of LVH
In RBBB, terminal QRS is oriented to the
Right and anteriorly
In LBBB, terminal QRS is oriented to the
Left and posteriorly
BBB that is more common in subjects without structural heart disease
RBBB
LBBB is the marker of one of 4 underlying conditions associated with increased risk of cardiovascular morbidity and mortality rates
- CAD
- Hypertensive heart disease
- Aortic valve disease
- Cardiomyopathy
Fascicular block where QRS axis is more negative than -45 degrees
LAFB
Fascicular block where QRS axis is more rightward than +110-1200
LPFB
Most common cause of marked LAD in adults
LAFB
Fascicular block that is more common
LAFB
LPFB is extremely rare as an isolated finding
In early transmural ischemia, the T wave is
hyperacute
Subendocardial ischemia manifests as _____ in the ECG
ST segment depression with ST elevation in aVR
Reciprocal ST depressions in leads V1 to V3 is seen in
Posterior wall ischemia
Reversible transmural ischemia due to coronary vasospasm
Prinzmetal’s angina
Ischemic chest pain with deep T-wave inversions in multiple precordial leads (e.g. V1-V4, I and aVL) with or without cardiac enzyme elevations is caused by severe obstruction in
LAD
CVA T wave pattern
Deep, wide T wave inversions
Scooping of the ST-T wave complex is an effect seen in what drugs
Digitalis
Relatively a specific ECG sign of pericardial effusion, usually with cardiac tamponade
Total electrical alternans (P-QRS-T) with sinus tachycardia
Gold standard in the assessment of the anatomy and physiology of the heart and its associated vasculature
Coronary angiography
T or F: Coronary angiography is mandatory prior to cardiac surgery in young patients who have CHD or VHD
False. as long as well-defined by non-invasive imaging or no CAD symptoms
Risk of MI in elective cardiac catheterization
<0.1
Risk of stroke in elective cardiac catheterization
0.01%
Risk of death in elective cardiac catheterization
0.1%
Most common complication of cardiac catheterization
Significant access-site bleeding – 1.5-2.0%
Contrast-induced AKI is defined as
increase in Crea >0.5 mg/dL or 25% above baseline that occurs 48-72 hrs after contrast
Prior to cardiac catheterization, you have to stop Metformin when?
24 hrs prior to the procedure until 48 hrs after – limit risk of lactic acidosis
In order to prevent CIN, when will you give NaHCO3? And dose?
3mL/kg per hour 1 hour prior and 6 hours
Prior to coronary angiography, how much Aspirin will you give patient?
325 mg Aspirin
Additional antiplatelet if procedure is likely to progress to PCI
• Clopidogrel – 600mg loading and 75 mg daily
• Prasugrel – 60 mg LD and 10 mg OD
• Ticagrelor – 180 mg LD and 90 mg BID
In patients who will undergo cardiac catheterization, you hold warfarin how many days prior? And target INR should be?
2-3 days prior
INR <1.7
In patients who will undergo cardiac catheterization, you hold NoAC how many days prior?
1-2 days
24-48 hrs
Vascular access for left heart catheterization (2)
Femoral or radial artery
Vascular access for right heart catheterization (3)
Femoral, brachial, or internal jugular vein
Test that confirm dual blood supply to the hand prior to radial approach of cardiac catheterization
modified Allen’s test or Barbeau test
Preferred access sites for cardiac catheterization to the right heart when IVC filter in place or requires prolonged hemodynamic monitoring
Internal jugular or antecubital veins
Direct thrombin inhibitors that may given instead of heparin for prolonged cardiac catherization (2)
Bivalirudin 0.75 mg/kg bolus, 1.75 mg/kg per hour for the duration of the procedure
Argatroban 350 ug/kg bolus, 15 ug/kg per min for duration of the procedure
During cardiac catheterization, if without VHD (based on pressure tracings), atria and ventricles are “one chamber” during what part of cardiac cycle?
Diastole
During cardiac catheterization, if without VHD (based on pressure tracings), ventricles and their respective outflow tract are “one chamber” during what part of cardiac cycle?
systole
During the hemodynamic study, if there is systolic pressure gradient between LV and aorta, it indicates
Aortic stenosis
During the hemodynamic study, if there is diastolic pressure gradient between the pulmonary capillary wedge (LA) pressure and the LV, it indicates
Mitral stenosis
During the hemodynamic study, a dynamic intraventricular pressure gradient during ventricular systole
HOCM
During a hemodynamic study, following a premature ventricular contraction, there is an increase in the LV-aorta pressure gradient with a simultaneous decrease in the aortic pulse pressure. What do you call this sign? And in what condition is it present?
Brockenbroigh-Braunwald sign
HOCM
Absent in AS
During hemodynamic study, if RA pressure is increased with decreased or absent y descent with diastolic equalization of pressures in all cardiac chambers, it is indicative of what condition?
Cardiac tamponade
Due to impaired RA emptying during diastole
During hemodynamic study, if there is elevated RA pressure with prominent y descent, it is indicative of what condition?
Constrictive pericarditis
Due to rapid filling of the RV during early diastole
Most specific hemodynamic phenomenon for constriction
Discordant pressure changes in the RV and LV with inspiration
• RV systolic pressure increases
• LV systolic pressure decreases
During hemodynamic study, marked increase in RV and pulmonary artery systolic pressures (>60 mmHg), separation of the LV and RV diastolic pressures by > 5 mmHg and concordant changes in the LV and RV diastolic filling pressures with inspiration (both increase) is indicative of
Restrictive cardiomyopathy
The amount of oxygen consumption by an organ is equal o the product of its blood flow (cardiac output) and the difference in the concentration of the substance in the arterial and venous circulation (A-V oxygen difference).
Fick method
Indicator for Fick method
Oxygen
Indicator for thermodilution method
Temperature
Mean pressure gradient / mean flow (cardiac output) =
Ohm’s law
Equates the area to the flow across the valve divided by the pressure gradient between the cardiac chambers surrounding the valve
Gorlin formula
Valve area and mean gradient indicative of severe aortic stenosis
Area <1.0 cm2 and a mean gradient of >40 mmHg
Valve area and mean gradient indicative of moderate-to-severe MS
Area <1.5 cm2 and a mean gradient >5-10 mmHg
Difference in O2 saturation of 5-7% between adjacent cardiac chambers is indicative of
Intracardiac shunts
Determine severity of the intracardiac shunt
Qp/Qs
For ASD, a Qp/Qs ratio of ___ is considered significant
1.5
For VSD, a Qp/Qs ratio of ___ with evidence of LV volume overload is a strong indication for surgical correction
≥2
Should be suspected in patients with subtherapeutic anticoagulation with a low mean INR, a prothrombotic state, recent onset heart failure, cardiogenic shock, cardiac arrest, thromboembolic event or, in asymptomatic patients, an increasing gradient across the prosthetic valve.
Prosthetic valve leaflet dysfunction
Three major coronary vessels evaluated in coronary angiography
Left anterior descending artery
Left circumflex artery
Right coronary artery
It is termed as right dominant when the ____ is the origin of what 3 arteries_____
RCA
AV nodal branch, the posterior descending artery, and the posterior lateral vessels
In terms of coronary circulation, 85% of individuals are right or left dominant?
Right dominant
It is termed as left dominant when the ____ is the origin of what 3 arteries_____
LCx
AV nodal branch, the posterior descending artery, and the posterior lateral vessels
Posterior descending vessel arise from both the right coronary and the posterior lateral vessels from left coronary circulation. This circulation is called _____ and seen in how many % of people?
Codominant circulation
10%
Most common coronary artery anomaly
Separate ostia for the LAD and LCx
Coronary stenosis that is considered significant
> 50%
Percent stenosis is determined visually by
comparing the most severely diseased segment with a proximal or distal “normal segment”
A portion of the vessel dips below the epicardial surface into the myocardium and is subject to compressive forces during ventricular systole
Myocardial bridge – most commonly involves the LAD
returns to normal during diastole unlike the stenosed part
A measure of the relative duration of time that it takes for contrast to opacify the coronary artery fully
Thrombolysis in myocardial infarction (TIMI) flow grade
TIMI flow grade 1
minimal filling of contrast
severe stenosis
TIMI flow grade 2
delayed filling of contrast
severe stenosis
Provides a more accurate anatomic assessment of the coronary artery and the degree of coronary atherosclerosis if with intermediate stenoses (40–70%), indeterminate findings, or anatomic findings that are incongruous with the patient’s symptoms
Intravascular ultrasound (IVUS)
A catheter-based imaging technique that uses near-infrared light to generate images with better spatial resolution than intravascular ultrasound, and image characteristics of the atherosclerotic plaque (lipid, fibrous cap) with high definition and assess coronary stent placement, apposition, and patency
Optical coherence tomography
Provides a functional assessment of the coronary stenosis and is more accurate in predicting long-term clinical outcome than imaging techniques
Fractional flow reserve
Ratio of the pressure in the coronary artery distal to the stenosis divided by the pressure in the artery proximal to the stenosis at maximal vasodilation
Fractional flow reserve
Fractional flow reserve that indicates hemodynamically significant stenosis that would benefit from intervention
<0.8
Bed rest duration for femoral and radial approach
6 hours
2 hours
For narrow QRS-complex tachycardia, ventricular activation is from the
Purkinje system
For wide QRS-complex tachycardia, ventricular activation is from the
Accessory pathway
Most common SVT
Sinus tachycardia
First step in diagnosis of SVT
Consider the possibility of sinus tachycardia
Among SVT, using AV nodal maneuvers or drugs may terminate tachycardia except for
Atrial flutter
Increased AV block with continueation of atrial flutter exposes underlying flutter waves
tachycardia from the normal sinus node area that occurs without an identifiable precipitating factor as a result of dysfunctional autonomic regulation
Inappropriate sinus tachycardia
Regular atrial tachycardia with defined p wave; may be sustained, nonsustained, paroxysmal, or incessant. Frequent sites of origin occur along the valve annuli of left or right atrium, pulmonary veins, coronary sinus musculature, superior vena cava
Focal atrial tachycardia (AT)
organized reentry creates organized atrial activity, commonly seen as sawtooth pattern at rates typically faster than 200 beats/min
Atrial flutter
chaotic rapid atrial electrical activity with variable ventricular rate
Atrial fibrillation
the most common sustained cardiac arrhythmia in older adults
Atrial fibrillation
multiple discrete p waves often seen in patients with pulmonary disease during acute exacerbations of pulmonary insufficiency
Multifocal atrial tachycardia
paroxsymal regular tachycardia with P waves visible at the end of the QRS complex or not visible at all
AV nodal reentry tachycardia (AVNRT)
the most common paroxysmal sustained tachycardia in healthy young adults
AV nodal reentry tachycardia (AVNRT)
paroxysmal sustained tachycardia similar to AV nodal reentry; during sinus rhythm, evidence of ventricular preexcitation may be present (Wolff-Parkinson-White syndrome) or absent (concealed accessory pathway)
Orthodromic AV reentry tachycardia (AVRT)
Either has no discernible p-waves because they are synchronous with the QRS, or p-waves that are negative in II, III, aVF immediately following the QRS (referred to as short R-P tachycardia)
AV nodal reentry tachycardia (AVNRT)
The most abundant superfamily of ion channels expressed in the heart
Voltage-gated channels
the primary carriers of depolarizing current in both the atria and the ventricles
Na and Ca channels
In cardiac physiology, this is a time when little current is flowing, and relatively minor changes in depolarizing or repolarizing currents can have profound effects on the shape and duration of the action profile
Plateau phase
underlies the property of automaticity characteristic of pacemaking cells in the SA and AV nodes, His-Purkinje system, coronary sinus, and pulmonary veins
Spontaneous (phase 4) diastolic depolarization
Normal or enhanced automaticity of subsidiary latent pacemakers if there is failure of more dominant pacemakers
Escape rhythms
Abnormal automaticity may produce what arrhythmias (3)
- Atrial tachycardia
- Accelerated idioventricular rhythms
- Ventricular tachycardia
membrane voltage oscillations that occur during or after an action potential
Afterdepolarizations
most common arrhythmia mechanism
Reentry
Class I antiarrhythmic drugs blocks
Na
Class II antiarrhythmic drugs blocks
β-adrenergic receptor
Class III antiarrhythmic drugs blocks
K
Class IV antiarrhythmic drugs blocks
Ca
Class I antiarrhythmic drug that have moderate potency and intermediate kinetics
Ia – quinidine, procainamide
Class I antiarrhythmic drug that have low potency and rapid kinetics
Ib – lidocaine, mexiletine
Class I antiarrhythmic drug that have high potency and slowest kinetics
Ic – flecainide, propaferone
Antiarrhythmic drugs that have both Class I and Class III actions (3)
Quinidine
Procainamide
Ranolazine
Antiarrhythmic drugs that have the actions of the all 4 classes (2)
Amiodarone
Dronedarone
Dofetilide is what class of antiarrhythmic drugs?
Class III
Ibutilide is what class of antiarrhythmic drugs?
Class III
Class Ia antiarrhythmics
quinidine, procainamide
Class Ib antiarrhythmics
lidocaine, mexiletine
Class Ic antiarrhythmics
flecainide, propaferone
Most common cause of imbalance between myocardial oxygen supply and demand leading to NSTEMI
Plaque rupture
% of NSTEMI patient that has left main coronary artery stenosis
10%
% of NSTEMI patient that has 3-vessel CAD
30%
% of NSTEMI patient that has 2-vessel CAD
20%
% of NSTEMI patient that has single-vessel CAD
20%
% of NSTEMI patient that has no apparent critical epicardial coronary artery stenosis
15%
May show an eccentric stenosis with scalloped or overhanging edges and a narrow neck on coronary angiography and is composed of a lipid-rich core with a thin fibrous caps
Vulnerable plaques
Chest discomfort in NSTEMI is severe and has at least one of 4 features:
- Occurrence at rest (or with minimal exertion)
- lasting >10 min
- Relatively recent onset (i.e., within the prior 2 weeks)
- Crescendo pattern, i.e., distinctly more severe, prolonged, or frequent than previous episodes
Anginal equivalents (4)
- Dyspnea
- Epigastric discomfort
- Nausea
- Weakness
Anginal equivalents are more common in (3)
- Women
- Elderly
- Diabetes mellitus
2 ECG findings in NSTEMI and which of the 2 is the most common?
- New ST-depression – in 1/3 of the patients
* T wave inversion – more common
Preferred markers of myocardial necrosis
Cardiac troponin I or T
Serial ECG and cardiac markers monitoring are done after how many hours of presentation of NSTEMI?
4-6 hours and 12 hours after presentation
Risk of early (30-day) mortality of NSTEMI
1-10%
Risk of recurrent ACS rate during 1st year:
5-15%
7 independent factors for Thrombolysis in Myocardial Infarction Trial:
- Age ≥ 65 years
- 3 or more of the traditional risk factors for coronary heart disease
- Known history of CAD or coronary stenosis of at least 50%
- Daily aspirin use in the prior week
- More than 1 anginal episode in the past 24 h
- ST segment deviation of at least 0.5 mm
- Elevated cardiac specific biomarker above the upper limit of normal
4 additional risk factors for Thrombolysis in Myocardial Infarction Trial (aside from the independent factors)
- Diabetes mellitus
- LV dysfunction
- Renal dysfunction
- Elevated BNP
Ambulation in NSTEMI is permitted if
No recurrence of ischemia or no elevation of cardiac biomarker for 12-24 h
In NSTEMI, initial anti-ischemic treatment should include these 4
- Bed rest
- Nitrates
- Beta blockers
- Inhaled oxygen in patients with O2 sat <90% and/or in those with heart failure and rales
Absolute contraindications for Nitrates (2)
- Hypotension
* Recent use of PDE-5 inhibitors
Target heart rate for NSTEMI
50-60
Recommended for patients with persistent symptoms or ECG signs of ischemia after treatment with full-dose nitrates and beta blockers
Calcium channel blockers (Verapamil and Diltiazem)
Second major cornerstone of treatment of NSTEMI
Antithrombotic therapy
Major cornerstone: anti-ischemic therapy
Initial dose of Aspirin in NSTEMI
162 mg of a rapidly acting preparation (oral non-enteric coated or IV)
Platelet P2Y12 receptor blocker that is rarely used due to poor tolerability
Ticlodipine
Thienopyridine that has irreversible blockade of the platelet P2Y12 receptor
Clopidogrel
Loading dose of Clopidogrel in NSTEMI
600 mg or 300 mg
2 newer P2Y12 inhibitors that are superior to clopidogrel in preventing recurrent cardiac ischemic events in randomized double-blind studies
Prasugrel
Ticagrelor
A thienopyridine that has higher level of platelet inhibition than clopidogrel
Prasugrel
Loading dose and maintenance dose of Prasugrel in NSTEMI
60 mg
10 mg/day
Loading dose and maintenance dose of Ticagrelor in NSTEMI
180 mg
90 mg/day
A novel, potent, reversible platelet P2Y12 inhibitor
Ticagrelor
A P2Y12 inhibitor that may have dyspnea early after administration (most often transient and infrequently serious)
Ticagrelor
Dual antiplatelet therapy (DAPT) have ___% relative reduction in cardiovascular death, MI or stroke compared to aspirin alone
20%
Triple antiplatelet therapy for NSTEMI is composed of
Aspirin + P2Y12 inhibitor + Glycoprotein IIb/IIIa inhibitors
Direct thrombin inhibitor that has similar in efficacy to either UFH and LMWH in treatment of NSTEMI
Bivalirudin
Indirect factor Xa inhibitor that has similar in efficacy to LMWH in treatment of NSTEMI
Fondaparinaux
Patient is closely observed and coronary arteriography is carried out if rest pain or ST-segment changes recur, positive biomarker, or evidence of severe ischemia on a stress test. This approach is called
Selective invasive approach
Severe ischemic pain that occurs at rest that is associated with transient ST-segment elevation
Prinzmetal’s variant angina
Caused by focal spasm of an epicardial coronary artery with resultant transmural ischemia and abnormalities in the LV function
Prinzmetal’s variant angina
Cause of spasm in Prinzmetal’s variant angina is
the hypercontractility of vascular smooth muscle due to adrenergic vasoconstrictors, leukotrienes, or serotonin
Transient coronary spasm on coronary angiography is the diagnostic hallmark of
Prinzmetal’s variant angina
Main therapeutic agents used for Prinzmetal’s variant angina (2)
- Nitrates
* Calcium channel blockers
May increase severity of ischemic episodes in Prinzmetal’s angina
Aspirin
due to sensitivity of coronary tone to modest changes in the synthesis of prostacyclin
5-year survival of Prinzmetal’s angina
~90-95%
How many % of Prinzmetal’s variant angina will experience MI?
20%
In stress myocardial perfusion imaging, which is preferred, exercise stress or pharmacologic stress?
Exercise stress
Downside: submaximal exercise or people unable to exercise
Pharmacologic stress that is used in stress myocardial perfusion imaging (2)
- Coronary vasodilators (adenosine, dipyridamole, regadenoson) – most commonly used
- ß1-receptor agonist (dobutamine)
Simplest application of cardiac CT
CT calcium scoring
Scoring that quantify coronary calcium
Agatson score
Based on Agatson scoring, define minimal, mild, moderate, and severe scores
- Minimal – 0-10
- Mild – 10-100
- Moderate – 100-400
- Severe - >400
T or F. CT calcium scoring has high cardiac prognostic value
True
Techniques for better image in CT coronary angiography (3)
- Breath holding
- Slowing of HR to 60 bpm – using IV or oral ß-blocker
- SL nitroglycerin – to enlarge the coronary lumen just prior to contrast injection
Primary imaging method to assess cardiac structure and function
Echocardiography
How to compute for EF based on EDV and ESV
(EDV – ESV)/EDV
Primary method in the assessment of the diastolic function
Echocardiography
Most accurate noninvasive technique to evaluate structure and ejection fraction of the RV
CMR
Specific pattern of regional RV dysfunction in acute PE wherein there is preservation of the RV wall motion in the basal and apical regions, and dyskinesis in the region of the mid RV free wall
McConnell sign
Highly specific for acute PE
In CIN, renal function usually returns to baseline within ____, without progressing to chronic renal failure
7-10 days
Diagnostic test used to assess the cadiac shunts
Agitated saline / Bubble study
+ bubbles in the left side of the heart – shunt
If it remains on the right chamber, no shunt
Hallmark of myocardial ischemia in stress echocardiography (2)
New regional wall motion abnormalities and reduced systolic wall thickening
Most common form of stress radionuclide imaging tests for CAD evaluation
SPECT myocardial perfusion imaging
One of the most valuable clinical applications of radionuclide perfusion imaging is for
risk stratification
CAC score that is predictive of a higher likelihood of obstructive CAD
High CAC scores (Agatson score > 400)
Agatson score < 400 – less effective in excluding CAD especially in symptomatic patients
For symptomatic patients without prior history of CAD and normal or nearly normal resting ECG who are able to exercise, what test should be used according to ACC/AHA recommendation?
exercise treadmill test
Low risk by exercise treadmill test is defined as those
Achieving >10 METS without chest pain or ECG changes
In patients who are categorized as low risk by exercise treadmill test but with CAD symptoms, what is ACC/AHA recommendation?
treat with medical therapy
High-risk Exercise Treadmill Testing findings (4)
- Typical angina with > 2 mm ST depression in multiple leads
- ST elevation during exercise
- Drop in BP
- Sustained V-tach
In patients who are categorized as high risk by exercise treadmill test, what is the next step based on ACC/AHA recommendations?
coronary angiography
Intermediate-high risk Exercise Treadmill Testing findings (3)
- Low exercise capacity
- Chest pain
- ST depression without high risk features
In patients who are categorized as intermediate-high risk by exercise treadmill test, what is the next step based on ACC/AHA recommendations?
additional testing (stress imaging or coronary CTA)
In patients who are unable to exercise and/or with abnormal resting ECGs (e.g. LVH with strain pattern and LBBB), what is recommended testing strategy?
imaging strategy
In patients who have intermediate-high likelihood of CAD (e.g. diabetics and renal impairment), what is recommended testing strategy?
imaging strategy – due to increased overall sensitivity for diagnosis of CAD and improved risk stratification
Justification of stress imaging
identification of which patients may benefit from a revascularization strategy rather than angiography-derived anatomic stenoses
First imaging test for the assessment of valvular heart disease
Echocardiography
Most cost-effective screening method for VHD
Echocardiography
Indications of echocardiography in VHD (4)
- Cardiac murmurs
- DOB
- Syncope or presyncope
- Preoperative exams in patients undergoing bypass surgery
Tethering of the leaflet tips and relative pliability of the leaflets themselves (hockey stick-type deformation particularly of anterior leaflet) is and echocardiographic finding of
Rheumatic MS
Best technique for imaging for presence or the extent of infarcted myocardium in MI patients
Late gadolinium enhancement imaging by CMR
Why not do echocardiography immediately after MI who underwent reperfusion therapy?
There is partial or complete recovery of ventricular function within several days (EF may be misleading at this time) – myocardial stunning
Best method in the assessment of patients with suspected mechanical complications after MI
Echocardiography