Cardiac Flashcards
Atrial Systole is…
The contraction of the right and left atria pushing blood into the ventricles
Atrial Diastole
The period between atrial contractions when the atria are repolarising
Ventricular systole
Contraction of the right and left ventricles pushing blood into the pulmonary artery and aorta
Ventricular diastole
period between ventricular contractions when the ventricles are repolarising
Ventricular PVCs are
Preventricular contractions characterised by: - Absent p wave - wide QRS Can occur in isolation or grouped. Serious when >6 per minute
Unifocal PVC - look the same Multifocal PVC - more than one shape. Trigeminal - every third rhytm Bigeminal every other beat Couplet - occur in pairs Triplet - three in a row
Ventricular fibrillation is characterised by
Absent p-wave and no QRS complex. Generally irregular
Pulseless emergency situation
Ventricular Tachycardia
Absent pwave, Fast rate. Wide and bizarre QRS. Run of 3 or more PVCs occurring sequentially
Atrial flutter
Saw tooth pattern - 250-350 for atrial rate. Ventricular often slower.
Atrial tachycardia
P wave- merged with T wave
150-250 bpm
Atrial fibrillation
Pwave absent or erratic
>350 but ventricular rate may be normal. If HR and BP are stable can still exercise.
if resting HR is above 115 or the patient is uncomfortable or responding poorly then stop and seek medical consult.
Abnormal heart enzymes
CK-MB - 2-4hours –> 12-24 hours –> 2-3 days
Cardiac troponin (normal <0.03) 2-4 hours –> 24-48 hours –> 14 days
CK 6 hours –> 12 hours –> 2-3 days
Preload
Tension in the ventricular wall at the end of diastole. Venous filling pressure of the left ventricle during diastole
Afterload
forces that impede the flow of blood out of the heart. Peripheral vascular pressure. Inversely proportional to stroke volume.
Stroke volume
volume of blood ejected by each contraction. Average 60-80ml.
Cardiac output
Amount of blood pumped from the left or right ventricle per minute 4.5-5L/min at rest. Product of SV and HR
Venous return.
Amount of blood returned to the right atrium each minute
S1 Heart sound
Normal, low pitch ‘Lub’ sound. Closure of the AV valves
S2 Heart sound
Normal higher pitched ‘dub’
S3 Heart sound
Abnormal - ventricular gallop. Passive flow of blood from atria during diastole.
S4 Heart sound
Abnormal - atrial gallop, ventricular filling and atrial contraction
Bruit
Abnormal blowing sound - atherosclerosis
Murmurs
Between S1 and S2 or S2 and S1 - valvar disease
Thrills
blood passing obstruction - occurs soon after S2
What are the locations of auscultation for the heart
Aortic Valve - 2nd space, (R) sternal border
Pulmonary Valve - 2nd space (L) sternal border
Tricuspid valve - 4th space (L) sternal border
Mitral valve - 5th space (L) mid clavicular
What are the absolute contraindications to exercise stress testing?
- Recent ECG change suggesting infarct or significant cardiac change
- Recent complicated MI
- Unstable angina
- uncontrolled ventricular arrhythmia
- atrial arrhythmia that compromises cardiac function
- 3rd degree AV heart block w/o pace maker
- acute congestive HF
- severe aortic stenosis
- Suspected or known dissecting aneurysm
- thromboplebitis or intra cardiac thrombi
- recent systemic or pulmonary embolus
- acute infections
- significant emotional distress (psychosis)
What are the relative contraindications to exercise
- Resting DBP > 115 or SBP > 200
- Moderate valvular heart disease
- Known electrolyte abnormalitis (hypokalemia, hypomagnesaemia)
- Frequent or complex ventricular ectopy, ventricular aneurysm
- uncontrolled metabolic disease, chronic infectious disease
- neuromusc, MS or Rheymatoid disorders exacerbated by ex
- advanced or complicated pregnancy
Karvonens formula
Target heart rate 60-80%= intensity % (max-resting) + resting HR
Adenosine and persantine are used for what
Chemical/Pharmacological stimulation for those who cannot perform exercise stress testing
Electrical activity of the heart occurs how
Atrial depolarisation via the SA node, Ventricular depolarisation via the AV node. Signal travels to the bundle of his and purkinje fibers
Pwave: PR interval: PR Segment: QRS complex: QT interval: ST segment: T wave:
Pwave: Atrial depolarisation
PR interval: Time of atrial depolarisation from SA to AV 0.12-.20s
QRS complex: Ventricular depolarization and atrial repolarization 0.04-0.10s
QT interval: Time for ventricular depolarisation and repolarisation 0.32-.40s
ST segment: time ventricles are depolarised (isoelectric)
T wave: Ventricular repolarision
Normal heart rate for babies and children
Babies: 100-160
Children aged 1-10: 60-140
Weak pulse can indicate
Low stroke volume and cardiogenic shock
Bounding pulse can indicate
Aortic insufficiency. Decreased peripheral pressure
1st degree heart block
Lengthened PR interval >0.2 seconds
Delayed conduction from atria to ventricles through AV node.
2nd degree heart block (type 1)
Progressively long PR interval to the point where QRS is dropped. often asymptomatic - presyncope may occur, may manifest as bradycardia on physical exam
2nd degree heart block (type 2)
Decrease of distal conduction system. PR interval steady, occasional dropped QRS complex
3rd degree heart block
Block in His-purkinje system. Life threatening. Requires ATROPINE and pacemaker. Associated with fatigue, dizziness, lightheaded, syncope and bradycardia.
Central line (swan-Ganz Catheter):
Measures central venous pressure, pulmonary artery pressure and pulmonary capillary wedge pressures
Signs and symptoms of cardiac distress
Angina, Dyspnea, Diaphoresis, Orthopnea, Blood pressure drop, Dizziness, Nausea/emesis, Ataxia, Xyanosis, Pallor, VT
ABI
Normal 0.95-1.2
Brachial artery in the arm and the dorsal pedis or the tibial posterior artery in the lower limb
Phase 1 of Cardiac rehab focuses on… and requires monitoring via… with a MET target of….
Strength focus with active assisted and active exercises aim for minimal assist with ADLs. Starting with lower extremities. Target 60-75% of maximal effort. Monitoring via telemetry ECG. Initial 1-2Mets progressing to 5 Mets by d/c
Phase 2 of Cardiac rehab focuses on… and requires monitoring via… With a MET target of
Focus on Strength. Exercises for UL and LL. 200ft ambulation by the end of the phase. Typically 4-6 weeks. Monitoring via vital signs and pulse oximeter during ex but not at rest. 9 METs by the end of phase.
Phase 3 of Cardiac rehab focuses on… and requires monitoring via… with a MET target of….
Focus on endurance. Monitoring before and after ex. End of phase when patient can moniotr their own vital signs and increase workloads to an appropriate stress level
5-9+ METs
Congestive heart failure stages are as follows:
Stage one: minimal problem completing 6.5Mets
Stage 2: moderate limitations completing 4.5 METs
Stage 3: marked limitation completing 3 METs
Stage 4: severe/unable to carry out activity up to 1.5 METs
Sternal precautions include
No pulling up in bed - must roll to sidelying
No pushing/pulling/lifting more than 10Lb for 6 weeks
No driving for 4 weeks
Avoid pushing up to stand with hands
Full neck, shoulder and torso ROM permitted - provided no skin or muscle flap present - if so <90 degrees at shoulder
Avoid Habd with ER
more conservative if DM or osteoporosis
Adverse responses to inpatient exercise leading to exercise termination
DBP > 110 Decrease in SBP >10mmHg Ventricular or atrial dysrhythmia Second or third degree heart block angina, marked dyspnea, ECG changes indicative of ischemia
Common cardiac changes due to aging
Changes due to inactivity and disease not age itself.
- Cardiac hypertrophy
decreased coronary blood flow
Thickening and stiffening valves
resting BP rises
Blunted CV response to ex
Max HR declines
Arteries thicken, slowed exchange through capillary walles, increased peripheral resistance.
Decreased SV due to decreased myocardial contractility
CO decreases 1% per year after age 20
Left sided heart failure occurs when and causes what
The heart cannot adequately pump blood into circulation - fluid backs up into the lungs - Fatiuge - dyspnea - persistent cough - Paroxysmal nocternal dyspnea - Orthopnea - Tachycardia Weakness - pulmonary oedma - weight gain - Cool dry skin
Right sided heart failure occurs when and causes what
The right side of the heart cant pump venous blood in the pulmonary circulation - fluid backs up into the body
- dependent edema
- cyanosis
- right upper quadrant pain
- fatigue
- jugular vein distension
- hepatomegaly
Venous insufficency
Occurs when there is inadequate drainage of venous blood from a body part. Leads to edema and skin abnormalities
Arterial insufficiency
Lack of adequate blood flow
Reading an ECG you should take the following 5 steps
- Rhythm - regular/irregular
- Heart rate (300, 150, 100, 75, 60)
- P wave
- PR interval (normal 3-5 small squares)
- QRS complex
Calcium channel blockers
- reduced calcium intake into smooth muscle - relax and widen blood vessels = Decreased HR, Decreased BP.
Use RPE. OH problematic
Pines - Amlodipine, felodipine, isradipine
Not atropine - used for 3rd degree heart block.
Betablockers
treatment for cardiac arrhythmia. Decreased myocardial Oxygen demand. Decreased HR, decreased contractility.
Decreased HR and BP.
Atenolol bisoprolol, metoprolol
Ace inhibitors
Treatment of HTN and CHF - reduced BP. may cause hyperkalemia. Benazepril, lisinopril, perindopril
Positive ionotropic agents
Increase force of contraction. Increases BP, slows HR - digitalis. Digitalis may cause muscle weakness.
