cardiology Flashcards
Most efficient extractor of oxygen
heart
Intracellular junctions responsible for the cardiac syncytium
Gap junctions
Substance that dilates upstream blood vessels
Endothelium-derived Relaxing factor (EDRF) aka Nitric Oxide (NO)
Most potent vasoconstrictor
ADH (can incrase levels of endothelin 1)
An increase in Venous return will increase the stroke voluume, Basisl Stretching of cardiac sarcomeres will increase contraction
Frank-Starling Mechanism
Hypertension, irregular respiration and bradycardia due to activation of the CNS ischemic response and baroreceptor reflex in increased intracranial pressure
Cushing Reflex
Formula for BP based on Ohm’s Law
BP = CO x TPR TPR= (HR x SV) x TPR
TPR is synonymous with systemic Vascular resistance and increases when arterioles vasoconstricted
Normal pressure at various parts of the adult circulation
Large Arteries = <120/80 mmHg Systemic Capillaries: 17 mmHg Vena Cava : 0 mmHg Pulmonary Artery: 25/8 mmHg Pulmonary Capillaries: 7 mmHg
Abdominojugular Reflux
At least 10 second pressure over the RUQ
(+) = sustained rise of >3 cm in JVP for at least 10-15 seconds after release of the hand
Pansystolic murmur of tricuspid regurgitation
Louder during inspiration and diminishes during forced expiration
Carvallo’s sign
High pitched, diastolic, decresendo blowing murur along the left sternal border due to dilation of the pulmonary valve ringl occurs in mitral valve disease and severe pulmonary hypertension
Graham Steell Murmur
Condition where the murmur of AS may be transmitted downward and to the apex and may be confused with the systolic murmur of mitral regurgitation
Gallavardin effect
Apical pulse is reduced and may retract in systole in constrictve pericarditis
Broadbent’s sign
A rapidly rising “water-hammer: pulse that collapses suddenly as arterial pressure falls rapidly during late systole and diastole, Seen in AR
Corrigan’s pulse
Capillary pulsation manifests as alternate flushing and paling of the skin while pressure is applied to the tip of the nail, seen in AR
Quincke’s pulse
A booming “pistol-shot” sound heard over the femoral arteries, seen in AR
Traube’s sign
To- and -fro murmur audible if the femoral artery is lightly compressed with a stethoscope, seen in AR
Duroziez Sign
Major noninvasive marker of increased CV morbidity/Mortality risk
LVH
Cornerstone in the diagnosis of acute and chronic ischemic Heart disease
ECG
ideal imaging modality for cardiac emergencies
2D echo
Gold standard for assessing LV mass and volumes
MRI
Triad of ruptured aneurysm
Left Flanked pain
hypotension
Pulsatile mass
Dx triad of Wolff-parkinson-white ECG pattern
wide QRS complex
Relatively short PR interval
Slurring of the initial part of the QRS complex (delta wave)
Triad of Chronic renal failure in ECG
Peaked T waves (hyperkalemia)
Long QT due to ST segment lengthening (hypocalcemia)
LVH (systemic hypertension)
3 principal features of tamponade (BECK’s TRIAD)
Hypotension
Soft/Absent heart sound
Jugular venous distension with a prominent x-descent but an absent y-descent
Plaques that have caused fatal thromboses tend to have……
Thin fibrous caps
Relatively large lipid cores
High content of macrophages
Major determinants of myocardial O2 demand
Heart rate
Myocardial contractility
Myocardial wall tension (stress)
triad of Buerger’s disease
Claudication of the affected extreminity
Raynaud’s phenomenon
Migratory superficial vein thrombophlebitis
Virchow’s triad
Stasis
Vascular/Endothelial damage
Hypercoaguability
Dressler’s triad (post-MI pericarditis)
fever
pleuritic pain
pericardial effusion
Drugs that increasses contractility
Digoxin
Dobutamine
Mlrinone
Drugs that reduces Preload
Diuretics
Vasodilators
ACE inhibitors, ARBS
Drugs that reduces afterload
Diuretics
Vasodilators
Ace inhibitors, ARBS
Beta Blockers
Class IA drug
MOA: Binds to activated sodium channels and blocks the flow of sodium ions into the cardiac myocyte (PROLONGS AP)
Clinical Use: Afib, Aflutter, VTach
Examples: Quinidine, Procainamide, Disopyramide
Class IB drug
MOA: Binds to both activated and inactivated sodium channels and blocks the flow of sodium ions in the cardiac myocyte (SHORTENS AP)
Clinical Use: Post ischemic arrythmia, V.Fib,V-tach
Examples: Lidocaine, Tocainamide, Mexiletene
Class IC drug
MOA: Binds to activated sodium channels and blocks the flow of sodium ions into the cardiac myocyte (NO EFFECT on AP)
Clinical use: Treatment of severe refractory Ventricular arrythia
Examples: Flecainide, Encainide, Propafenone
Class II drugs
MOA: Blocks beta-adrenergic receptors
Clinical use: Numerous
Examples: Propanolol, metoprolol
Class III drugs
MOA: Binds potassium channels and blocks the flow of K in the myocyte (PROLONGS AP)
Clinical use: Atrial and ventricular arrythmias
Examples: Sotalol, Ibutilide, Bretylium, Amiodarone
Class IV drugs
MOA: Blocks voltage-gated calcium channels therbey blocking the flow of calcium into the cells
Clnical use: Supraventricular tachycardia rate reduction in patients with Afib
[Antihypertensive Drug] that causes Na excretion and reduction in blood volume
diuretics
[Antihypertensive Drug] Calcium channel blocker that exerts more effect on the vessels than the heart
dihydropyridines
nifedipine, felodipine, amlodipine
[Antihypertensive Drug] Calcium channel blocker that exerts more effect on heart than the vessels
Nondihydropyridines
verapamil, Diltiaem
[Antihypertensive Drug] Decreases the work load of the hear
Beta blockers
[Antihypertensive Drug] Blocks the AT1 receptor of angiotensin II
ARBs
[Antihypertensive Drug] Notorious for drug-induced cough by increasing bradykinins
ACE inhibitors
[Antihypertensive Drug] Blocks aldosterone action in the collecting tubules
Spironolactone, Eplerenone
[Antihypertensive Drug] Hypertension with benign prostatic hyperplasia
alpha-1 anatagonists (Prasozin)
[Antihypertensive Drug] Maintenance medication for pre eclampsia
methyldopa
Physiologic basis for normal ECG tracing
P wave: atrial depolarization
QRS complex: ventricular depolarization
T wave: ventricular repolarization
Master pacemaker of the heart
SA node
Causes of depolarization of the SA node
Calcium influx (sodium influx will merely bring potential closer to threshold; however sodium is still the determinant of heart rate)
Chronotropic Incompetence
Failure to increase heart rate during exercise, alternatively defined as:
1) Unable to achieve 85% of predicted maximal heart rate
2) Unable to achieve a heart rate >100 bpm with exercise
Maximal HR with exercise <2 SD below that of the age -matched control population
The only electrical connection between the atria and ventricles
AV node
Most common arrythmia mechanism
Reentry
Only reliable therapy for symptomatic bradycardia in the absence of extrinsic and reversible etiologies
Permanent pacemaking
Most rapid conduction in the heart
His bundle and bundle branchers
Most expeditious technique in the manangement of AV conduction block
transcutaneous pacing
Most common arrythmia identified during extended ECG monitoring
Atrial premature complexes
Most common sustained arrythmia
Atrial fibrillation
Has prolongation of PR befored dropped QRS complex
Mobitz type I
Has no prolangation of PR interval befored dropped QRS complex
Mobitz type II
Duration that distinguishes sustained from nonsustained ventricular tachycardia
> 30 seconds
Most common arrythmia post-MI
Premature Ventricular Contraction
Most common lethal arrythmia post MI
Ventricular Fibrillation