Cardiology
13 high-yield topics. Open a topic to review its pearls.
Heart Sounds
S1, S2, S3, S4 and splitting
The Four Sounds
- S1: Closure of AV valves (mitral + tricuspid) — onset of systole
- S2: Closure of ventricular outflow valves (aortic + pulmonic) — end of systole
- S3: Rapid ventricular filling in mid-diastole — physiologic in children & pregnancy; pathologic in adults (poor prognosis in CHF)
- S4: Atrial contraction against a noncompliant/stiff ventricle — late diastole; heard with LVH from any cause (HTN, HOCM, AS, ischemia)
Loud vs Soft S1
- Loud S1: Mitral stenosis, short PR (WPW), thyrotoxicosis, tachycardia
- Soft S1: Mitral regurgitation, long PR, poor LV function (increased LVEDP), severe MS
S2 Splitting
- Physiologic split: happens during inspiration
- Wide (A2P2): MR, VSD, pulmonic stenosis, RBBB
- Fixed split: ASD (+ mid-diastolic rumble)
- Paradoxical split (P2A2): aortic stenosis, LBBB, HTN
Pulse Findings
- Hyperkinetic: thyrotoxicosis, PDA (high-output states)
- Pulsus paradoxus: tamponade, constrictive pericarditis, PE
- Pulsus bisferiens: HOCM (rapid upstroke)
- Pulsus tardus: aortic stenosis (slow rise, poor prognosis)
Murmurs
Systolic, diastolic, and maneuvers
Auscultation Areas
- Right 2nd ICS: Aortic (AS, AI)
- Left 2nd ICS: Pulmonary (PS, PI, PDA)
- Left lower sternal border: Tricuspid (TS, TI, ASD, VSD, HOCM)
- Apex: Mitral (MS, MR)
Systolic Murmurs
- Holosystolic: MR, TR, VSD
- Mid-systolic (crescendo-decrescendo): AS, PS
- Late systolic: MVP (with click)
Diastolic Murmurs
- Early diastolic: AI, PI
- Mid-diastolic: MS, TS, ASD
- Late diastolic "plop": atrial myxoma
- Continuous: PDA
Maneuvers (increasing flow increases murmur)
- Inspiration: right-sided murmurs increase
- Expiration: left-sided murmurs increase
- Standing/Valsalva: increases HOCM & MVP, decreases the rest
- Squatting/hand grip: increases MVP/MR, decreases HOCM
- Echo justified for diastolic murmurs and grade ≥3 systolic murmurs
Coronary Artery Disease
ACS, risk stratification, biomarkers
Coronary Anatomy (EKG leads)
- LAD: anterior/anterolateral LV + anterior septum → V1-V4
- Left circumflex: lateral LV → I, aVL, V5, V6
- RCA: inferior LV + inferior septum → II, III, aVF
Risk Factors
- Unmodifiable: age, male sex, family history of premature CAD
- Modifiable: HTN, DM, hypercholesterolemia, smoking, sedentary lifestyle
- Best advice to young worried patient: quit smoking
- TIMI score components: age >65, ≥3 risk factors, known CAD, ASA use, severe angina, elevated markers, ST deviation
UA / NSTEMI
- Angina at rest usually >20 min, new onset, or increasing
- Pathophysiology: acute plaque rupture → non-occlusive thrombus
- NSTEMI releases cardiac biomarkers; UA does not
- ST depression = ischemia
STEMI Management
- ASA, morphine, IV nitroglycerin, IV beta blockers
- Reperfusion: PCI (recanalize culprit within 90 min) or thrombolytics
- LBBB new onset treated as STEMI
- Post-MI ASA dose is 325 mg (not 81)
Cardiac Biomarkers
- Troponin: positive 3-6h, peaks 10-24h, normalizes 5-15 days
- CK-MB: positive 3-8h, peaks 10-36h, normalizes 6-10 days
- Myoglobin: earliest to rise
Post-MI Complications
- RV infarct (inferior MI): hypotension, elevated JVP, clear lungs → aggressive IVF, NO nitro
- VSD: new pansystolic murmur + thrill, O2 step-up
- Papillary muscle rupture: holosystolic murmur at apex, large V wave
- Free wall rupture: tamponade, sudden PEA death
- Dressler syndrome (day 10): pericarditis → indomethacin or ASA
Congestive Heart Failure
Systolic vs diastolic, staging, mortality drugs
Key Diagnostic Pearls
- First test to order: Echo
- All systolic CHF: do cardiac cath to r/o ischemia
- Pro-BNP normal = not CHF (obese have false low); high = dilation of any cause
- Sudden florid failure = systolic; gradual = diastolic
Systolic vs Diastolic
- Systolic: decreased contractility, EF <40%, dilated LV, S3 gallop
- Diastolic: decreased relaxation, EF normal, concentric LVH, S4 gallop
- Diastolic strongly associated with HTN and DM
ACC/AHA Staging
- A: risk factors, no structural disease, no symptoms
- B: structural disease, no symptoms
- C: structural disease + symptoms
- D: refractory/end-stage disease
Drugs Improving MORTALITY
- ACE inhibitors (maximize dose)
- ARBs
- Beta blockers (NOT in acute decompensation)
- Spironolactone (NYHA III/IV)
- Hydralazine + nitrates (African Americans NYHA III/IV intolerant to ACEI)
- AICD for EF <35% documented 3-6 months
- BiV device (resynchronization) if QRS >120 ms
Drugs Improving SYMPTOMS Only
- Diuretics (discontinue if not overloaded)
- Long-acting calcium channel blockers
- Digoxin (decreases hospitalizations)
- Regular exercise program
Congenital Heart Disease
ASD, VSD, PDA, coarctation, Marfan
Atrial Septal Defect
- Ostium secundum most common
- Findings: fixed split S2, systolic ejection murmur, RBBB
- Ostium primum associated with Downs syndrome, AV valve abnormalities
- Complication: atrial fibrillation, paradoxical embolism/stroke
- Surgery if shunt ratio ≥1.7:1 or RV volume overload; NO surgery in Eisenmenger
Other Defects
- VSD: systolic murmur at LSB, most common in children, most close spontaneously
- PDA: machinery murmur, associated with maternal rubella, differential cyanosis
- Coarctation: femoral-brachial delay, rib notching, seen in Turner syndrome
Marfan Syndrome
- Autosomal dominant, fibrillin gene mutation
- Aortic dilation → risk of dissection/rupture
- Yearly echo until root reaches 4.5 cm, then every 6 months
- Beta blockers reduce dilation; surgery at diameter >5.5 cm
Eisenmenger Syndrome
- L→R shunt develops pulmonary HTN → shunt reversal (R→L) → cyanosis
- Clubbing, secondary polycythemia
- Treatment: phlebotomy if Hct >65
- Pregnancy contraindicated (mortality >50%)
Valvular Heart Disease
AS, AI, MS, MR, MVP
Aortic Stenosis
- Triad: syncope, chest pain, decompensated CHF → surgical treatment if good functional capacity
- Severe: paradoxical split S2, late peaking, S4; gradient >70, area <0.7 cm²
- Severe AS is contraindication to elective surgery (Pre-Op)
- Pre-op AVR needs cardiac cath to rule out CAD
Aortic Insufficiency
- Symptomatic OR LVEF <50% → surgery
- Asymptomatic + normal EF: follow with echo, assess LV dimensions
- AI + HTN: use arteriodilators (AS + HTN: avoid them)
Mitral Stenosis
- Causes left atrial dilation and atrial fibrillation
- Rx: negative chronotrope (BB or CCB) to increase diastolic filling
- Valvuloplasty if area <1.3 cm²
Mitral Regurgitation & MVP
- Treat MR if symptomatic OR LV end-systolic dimension >35 mm
- General rule: treat stenosis late, treat insufficiency early
- MVP: most common valve problem; mid-systolic click + murmur at apex
- Click moves earlier with standing/Valsalva
Arrhythmias
AF, flutter, SVT, WPW, VT, sudden death
Atrial Fibrillation
- Irregularly irregular, no P waves
- Rate control > rhythm control (decreases stroke risk, hospitalizations)
- CHADS2-VASc guides anticoagulation
- If >48h: rate control + anticoagulate OR TEE-guided cardioversion
- Warfarin 3-4 weeks before and 4 weeks after cardioversion
Rate & Rhythm Control
- Rate: beta blockers (exercise-induced), CCB (preserved EF/COPD), digoxin (low EF)
- Rhythm: amiodarone, sotalol, procainamide, electrical cardioversion
- CHADS2: CHF, HTN, Age >75, DM, Stroke/TIA
SVT & WPW
- AVNRT most common (reentry within AV node)
- AVRT: accessory pathway outside node
- SVT treatment: vagal maneuvers, adenosine (6 then 12 mg)
- WPW: short PR, delta wave, wide QRS
- WPW with wide-complex tachy: give procainamide — NO AV nodal blockers (BB/CCB/digoxin)
Ventricular Arrhythmias
- Torsades: polymorphic VT, prolonged QT → magnesium sulfate, d/c offending agent
- VT: >3 sequential PVCs at rate >150; sustained if >30 sec
- High-risk VT (EF <35%, CAD): EPS-guided ICD placement
Sudden Cardiac Death
- Most common cause: VT/VF
- Old patient: ischemic heart disease
- Young patient: HOCM (LVH on EKG) or Brugada (ST elevation V1-V3, sodium channelopathy)
- Best prevention: AICD placement
- Young patient with palpitations + syncope: do tilt table test first, not sudden death
AV Block
First, second, third degree; pacemaker indications
Types
- First degree: PR >0.2 sec, constant
- Mobitz I (Wenckebach): progressive PR prolongation then dropped QRS (common with BB/CCB/digoxin)
- Mobitz II: constant prolonged PR with sudden dropped QRS
- Third degree: atria and ventricles beat independently
Pacemaker Indications
- Second degree Mobitz II
- Third degree AV block
- Symptomatic bradycardia (sick sinus)
- Heart rate <40 bpm (awake)
- Carotid sinus hypersensitivity with asystole >3 sec
- Mobitz II with bifascicular block
Clinical Pearls
- Asymptomatic CAD + Mobitz I: decrease BB dose, dont stop it
- Posterior/inferior MI: transient Mobitz II
- Anterior MI: permanent Mobitz II, needs PPM
- AV block in endocarditis = paravalvular abscess → call CT surgery
Cardiomyopathies
Dilated, restrictive, hypertrophic
Dilated
- Most common non-ischemic; ventricular dilation, impaired systolic function
- Causes: idiopathic, toxins (ETOH, anthracycline), HIV, thiamine deficiency, peripartum, familial
- S3, mitral/tricuspid regurgitation murmur
- Treat like CHF (ACEI, BB, diuretics)
Restrictive
- Small ventricular cavity, diastolic dysfunction, elevated filling pressures
- Causes: amyloidosis, sarcoidosis, hemochromatosis, endomyocardial fibrosis
- EKG: low voltage; fat pad/rectal biopsy for amyloid
- Treat underlying cause, salt restriction, diuretics
Hypertrophic (HOCM)
- Variable LV hypertrophy, hyperdynamic function, LV outflow obstruction
- Systolic ejection murmur at LSB, intensifies with standing/Valsalva
- EKG: LVH, abnormal Q waves; asymmetric septal thickening on echo
- Treat: avoid vigorous sports, beta blockers/CCB, AICD, septal myotomy
- Poor prognosis: age <30, VT, syncope, failure to increase BP on exercise
Aortic Aneurysm / Dissection
Thoracic and abdominal
Overview
- Dilation ≥1.5× normal or ≥3 cm
- Risk factors: Caucasian, smoking, male, age >60, family history
Thoracic
- Causes: Marfan, atherosclerosis, vasculitis, syphilis
- Chest pain radiating to back; acute AR murmur
- Widened mediastinum on CXR; CT chest with contrast (TEE if contrast contraindicated)
- Surgery: >5.0 cm ascending, >6.0 cm descending, or expanding >1 cm/year
Abdominal
- Atherosclerotic >90%
- Pulsatile mass + hypotension + pain = rupture
- Surgery >5.5 cm or expanding >0.5 cm in 6 months
- Screening: male ex-smokers 65-75, one abdominal ultrasound
Medical Treatment
- Activity restriction, beta blockers, nitroprusside if dissection
- Modify risk factors (quit smoking)
Hypertension
Staging and drug choices
Staging
- Stage 1: SBP >140 or DBP >90
- Stage 2: SBP >160 or DBP >100
- BP goal ≥60 years: <150/90
Drug of Choice by Condition
- New mild HTN: thiazide (amlodipine also good in African Americans)
- LVH/DM/renal with proteinuria: ACEI
- CAD: BB or CCB
- s/p MI: BB and ACEI
- CHF: ACEI, carvedilol, loop diuretics
- Pregnancy: labetalol, methyldopa, hydralazine
- BPH: tamsulosin/prazosin
- Cocaine: labetalol or alpha blocker (never BB alone)
Emergencies
- Symptoms/EKG strain: IV labetalol, IV nifedipine, IV enalaprilat
- CVA: IV nicardipine
- Pulmonary edema: IV nitroglycerin, IV furosemide
- Dissection: IV BB or nitroprusside
- Pheochromocytoma: labetalol, phentolamine
- End organ damage: check fundus first
Acute Pericarditis
Diagnosis, EKG stages, treatment
Etiology & Symptoms
- Idiopathic 85-90%, infectious, post-MI, post-cardiac surgery, neoplasm, autoimmune, uremia
- Retrosternal chest pain, pleuritic, worse supine, improved sitting forward
- Radiates to neck, shoulder, trapezius
Exam & EKG
- Friction rub (85%): scratchy sound at LSB, sitting forward
- Stage I: diffuse ST elevation + PR depression (except aVR)
- Stage II: normalization
- Stage III: T-wave inversions
- Stage IV: normalization of T waves
Treatment
- NSAIDs (indomethacin, ASA, ibuprofen)
- Colchicine +/- ibuprofen for recurrent
- Steroids only for connective tissue disease or refractory (can cause recurrence)
Related Conditions
- Constrictive pericarditis: Kussmaul sign, pericardial knock, thickened pericardium → surgical stripping
- Symptomatic large effusion: pericardiocentesis (pericardiectomy if recurrent)
Peripheral Vascular Disease
Diagnosis and treatment
Key Points
- Risk factors: smoking, DM, hyperlipidemia, HTN, age
- Mesenteric ischemia: acute (Afib) or chronic (post-prandial pain)
- Lower extremity: ulcers and claudication
- Diagnosis: ABI/PVR <0.9
- Rx: ASA or Plavix, cilostazol, vascular surgery consult
- ACEI and statins cardioprotective; statins reduce mortality
- Renal artery stenosis (uncontrollable HTN): MRA/renal Doppler/angio