4.1 Cardiovascular Assessment & Diagnostics

Cardiac Physical Assessment

Proceed in the classic order: inspection, palpation, and auscultation. Use the bell of the stethoscope for low-pitched sounds (S3, S4, the rumble of mitral stenosis) and the diaphragm for high-pitched sounds (S1, S2, most murmurs, friction rubs).

Heart Sounds

• S1 (lub) — closure of the mitral and tricuspid (atrioventricular) valves; loudest at the apex; marks the beginning of systole
• S2 (dub) — closure of the aortic and pulmonic (semilunar) valves; loudest at the base; marks the end of systole; physiologic splitting occurs with inspiration
• S3 (ventricular gallop) — occurs in early diastole from rapid ventricular filling against volume overload; an early sign of heart failure; best heard at the apex with the bell with the patient in the left lateral position
• S4 (atrial gallop) — occurs in late diastole as the atria contract against a stiff, noncompliant ventricle (hypertension, prior myocardial infarction, aortic stenosis); always abnormal in adults

Murmur Grading

Murmurs are graded on intensity from 1 to 6:

Note the murmur's timing (systolic vs diastolic), location, radiation (aortic stenosis radiates to the carotids; mitral regurgitation to the axilla), and change with position.

JVD, Perfusion, and Edema

Assess jugular venous distension (JVD) with the head of bed at 30-45 degrees; distension more than 3-4 cm above the sternal angle reflects elevated central venous pressure from right heart failure, fluid overload, or cardiac tamponade. Grade peripheral pulses on a 0 to 4+ scale (0 absent, 1+ weak, 2+ normal, 3+ full, 4+ bounding). Capillary refill should be under 2-3 seconds. Grade pitting edema from 1+ (2 mm indentation) to 4+ (8 mm deep pit persisting more than 2 minutes). Also document skin temperature, hair distribution, and dependent rubor, which point to peripheral arterial disease.

Chest Pain Characterization

Use PQRST (provocation, quality, radiation, severity, timing) to distinguish cardiac from noncardiac pain.

• Stable angina — predictable, exertional chest pressure relieved within minutes by rest or nitroglycerin
• Unstable angina — new, worsening, or occurs at rest; part of acute coronary syndrome (ACS) and treated as a medical emergency
• Myocardial infarction (MI) — substernal crushing pressure radiating to the jaw, left arm, or back, with diaphoresis, nausea, and dyspnea; lasts more than 20 minutes and is not relieved by rest. Women, older adults, and patients with diabetes often present atypically: fatigue, indigestion, jaw pain, or dyspnea without chest pain
• Noncardiac causes — pleuritic pain is sharp and worse with inspiration; musculoskeletal pain is reproducible with palpation; gastrointestinal pain is burning and meal-related

12-Lead ECG Essentials

• Normal rate 60-100 beats/min; key intervals: PR 0.12-0.20 s, QRS < 0.12 s, QTc < 0.44-0.46 s (a prolonged QT predisposes to torsades de pointes)
• Know contiguous leads: inferior II, III, aVF (right coronary artery); septal/anterior V1-V4 (left anterior descending); lateral I, aVL, V5, V6 (circumflex). ST elevation of 1 mm or more in two or more contiguous leads suggests ST-elevation MI (STEMI)
• Obtain a right-sided ECG (lead V4R) to detect right ventricular infarction; these patients are preload dependent, so avoid nitroglycerin

Cardiac Biomarkers

• Troponin I/T is the gold standard for myocardial injury: it rises in 3-6 hours (1-3 hours with high-sensitivity assays), peaks at 12-24 hours, and remains elevated 7-10 days or longer. Draw serial values at presentation and again at 3-6 hours; a single negative value does not rule out MI
• B-type natriuretic peptide (BNP) is released with ventricular stretch: above 100 pg/mL suggests heart failure and above 400 pg/mL is strongly positive. NT-proBNP cutoffs rise with age (roughly above 450 pg/mL under age 50, above 900 for ages 50-75, above 1800 over 75). BNP helps differentiate dyspnea from heart failure versus pulmonary disease

Noninvasive and Invasive Diagnostics

Echocardiography

An echocardiogram measures ejection fraction (EF); 50-70% is normal. It also assesses wall motion, valve function, and chamber size. A transesophageal echocardiogram (TEE) requires sedation; keep the patient NPO until the gag reflex returns after the procedure.

Stress Testing

• Exercise treadmill testing raises myocardial oxygen demand to provoke ischemia (ST-segment depression or symptoms). Patients should not smoke or consume caffeine beforehand, and beta blockers may be held per orders
• Pharmacologic stress with adenosine, dipyridamole, regadenoson, or dobutamine is used when the patient cannot exercise. Withhold caffeine 12-24 hours before vasodilator agents because caffeine blocks their effect. Report chest pain, ST changes, or severe dyspnea immediately

Cardiac Catheterization: Preparation

Obtain informed consent. Assess for allergy to iodine-based contrast dye and shellfish; check renal function (creatinine, estimated glomerular filtration rate) because contrast is nephrotoxic; hold metformin per protocol to reduce lactic acidosis risk if renal function declines. Keep the patient NPO 6-8 hours and document baseline peripheral pulses. The catheterization also measures intracardiac pressures; the pulmonary capillary wedge pressure reflects left ventricular end-diastolic pressure.

Cardiac Catheterization: Post-Procedure Care

• Femoral approach: keep the affected leg straight with bedrest 2-6 hours depending on closure method; limit head of bed elevation; check the puncture site and distal pulses every 15 minutes initially, then per protocol
• Watch for bleeding, expanding hematoma, and retroperitoneal hemorrhage (sudden hypotension with flank or back pain)
• The radial approach allows earlier ambulation with a compression wristband
• Encourage fluids to flush the contrast; report chest pain or a cool, numb, mottled limb immediately

Pearl: the priority post-catheterization finding is an absent or weakening pedal pulse, which suggests arterial occlusion and must be reported immediately.