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ULY CLINIC
ULY CLINIC
10 Septemba 2025, 11:35:37
Gallop, Atrial (S4)
An atrial or presystolic gallop (S4) is an extra low-pitched heart sound occurring late in diastole, immediately before S1. Best heard with the bell of the stethoscope at the cardiac apex, S4 results from forceful atrial contraction against a stiff or noncompliant ventricle. Mnemonically, its cadence resembles “Ten-nes-see” (Ten = S4; nes = S1; see = S2).
Pathophysiology
S4 arises from atrial contraction into a ventricle with reduced compliance, as seen in left ventricular hypertrophy, ischemic heart disease, or restrictive cardiomyopathy. Left-sided S4 reflects left atrial contraction against a stiff left ventricle (e.g., hypertensive heart disease, aortic stenosis, cardiomyopathy), while right-sided S4 indicates right atrial contraction against a stiff right ventricle (e.g., pulmonary hypertension, pulmonary stenosis). The sound does not vary with respiration and often signifies diastolic dysfunction.
History and Physical Examination
History: Ask about hypertension, angina, valvular disease, cardiomyopathy, or prior myocardial infarction. Inquire about anginal symptoms (tightness, pressure, radiation), dyspnea, syncope, and exercise tolerance.
Examination: Auscultate at the apex (left-sided) or lower left sternal border (right-sided). Note timing in relation to S1, S2, and respiration. Assess for associated murmurs, S3, jugular venous distention, peripheral edema, and signs of heart failure.
Medical Causes
Condition | Mechanism & Clinical Notes | Associated Findings |
Angina | Transient S4 during anginal episodes; forceful atrial contraction in ischemic myocardium | Chest pain, dyspnea, diaphoresis, tachycardia |
Aortic Stenosis | Left ventricular hypertrophy reduces compliance | Harsh systolic ejection murmur, syncope, dyspnea, angina |
Aortic Insufficiency (acute) | Sudden volume overload stiffens LV | Soft diastolic murmur, tachycardia, dyspnea, crackles |
AV Block (1°–3°) | Bradycardia prolongs diastolic filling; S4 intensity varies | Hypotension, dizziness, fatigue, syncope |
Cardiomyopathy | Reduced ventricular compliance in dilated, hypertrophic, or restrictive forms | Dyspnea, orthopnea, palpitations, S3, edema |
Hypertension | LV hypertrophy reduces compliance | Often asymptomatic; may have headache, fatigue, dizziness |
Myocardial Infarction | Noncompliant myocardium due to ischemia | Crushing chest pain, dyspnea, diaphoresis, pallor |
Pulmonary Embolism (right-sided S4) | Increased RV stiffness | Tachypnea, tachycardia, dyspnea, cyanosis, pleuritic chest pain |
Thyrotoxicosis | High-output state increases atrial contribution | Tachycardia, palpitations, weight loss, tremor, dyspnea |
Special Considerations
Rapidly assess patients with chest pain for myocardial ischemia.
Monitor vital signs, oxygen saturation, and signs of heart failure.
Prepare for ECG, echocardiography, cardiac biomarkers, and, if indicated, cardiac catheterization or lung scan.
Patient Counseling
Educate patients on monitoring pulse rate and recognizing angina or heart failure symptoms.
Stress adherence to follow-up visits and lifestyle modifications for hypertension and cardiac risk reduction.
Pediatric & Geriatric Considerations
Pediatric: S4 may be normal after exercise but can also indicate congenital heart disease (e.g., ASD, VSD, PDA, severe pulmonary stenosis).
Geriatric: S4 intensity relative to S1 increases with age due to reduced ventricular compliance; may be physiologic in older adults.
References
Chen, J., Dharmarajan, K., Wang, Y., & Krumholz, H. M. (2013). National trends in heart failure hospital stay rates, 2001 to 2009. Journal of the American College of Cardiology, 61(10), 1078–1088.
Jhund, P. S., Macintyre, K., Simpson, C. R., Lewsey, J. D., Stewart, S., Redpath, A., … McMurray, J. J. (2009). Long-term trends in first hospitalization for heart failure and subsequent survival between 1986 and 2003: A population study of 5.1 million people. Circulation, 119(4), 515–523.