Prevalence and predictors of audible physiological third heart sound in a population sample aged 36 to 37 years

Third and Fourth Heart Sounds and Myocardial Fibrosis in Hypertrophic Cardiomyopathy

BACKGROUND

The 4th heart sound (S4) is commonly heard in patients with hypertrophic cardiomyopathy (HCM). The 3rd heart sound (S3) is also audible in HCM patients regardless of the presence or absence of heart failure. These extra heart sounds may be associated with myocardial fibrosis because myocardial fibrosis has been suggested to affect left ventricular compliance.Methods and Results:The present retrospective study evaluated 53 consecutive HCM patients with sinus rhythm who had no symptoms of heart failure and underwent an initial assessment including phonocardiography, echocardiography, and late gadolinium enhancement (LGE) magnetic resonance imaging (MRI). S3 was detected on phonocardiography in 13% of all patients, and S4 was recorded in 75% of patients. Patients with S3 had a higher incidence of LGE and larger LGE volumes (86% and 11.5±2.4 g/cm, respectively) than patients without S3 (33% and 2.5±0.8 g/cm, respectively; P=0.02 and P=0.002). The presence of S4 was not associated with MRI findings, including the incidence of LGE and LGE volume. The diagnostic value of S3 for the detection of LGE was highly specific (97%), with a low sensitivity (29%).

CONCLUSIONS

Myocardial fibrosis, as assessed by LGE, was associated with S3 but not with S4 in patients with HCM. These results may contribute to the risk stratification of patients with HCM.

Cardiac Auscultation for Noncardiologists: Application in Cardiac Rehabilitation Programs: PART I: PATIENTS AFTER ACUTE CORONARY SYNDROMES AND HEART FAILURE

During outpatient cardiac rehabilitation after an acute coronary syndrome or after an episode of congestive heart failure, a careful, periodic evaluation of patients' clinical and hemodynamic status is essential. Simple and traditional cardiac auscultation could play a role in providing useful prognostic information.Reduced intensity of the first heart sound (S1), especially when associated with prolonged apical impulse and the appearance of added sounds, may help identify left ventricular (LV) dysfunction or conduction disturbances, sometimes associated with transient myocardial ischemia. If both S1 and second heart sound (S2) are reduced in intensity, a pericardial effusion may be suspected, whereas an increased intensity of S2 may indicate increased pulmonary artery pressure. The persistence of a protodiastolic sound (S3) after an acute coronary syndrome is an indicator of severe LV dysfunction and a poor prognosis. In patients with congestive heart failure, the association of an S3 and elevated heart rate may indicate impending decompensation. A presystolic sound (S4) is often associated with S3 in patients with LV failure, although it could also be present in hypertensive patients and in patients with an LV aneurysm. Careful evaluation of apical systolic murmurs could help identifying possible LV dysfunction or mitral valve pathology, and differentiate them from a ruptured papillary muscle or ventricular septal rupture. Friction rubs after an acute myocardial infarction, due to reactive pericarditis or Dressler syndrome, are often associated with a complicated clinical course.During cardiac rehabilitation, periodic cardiac auscultation may provide useful information about the clinical-hemodynamic status of patients and allow timely detection of signs, heralding possible complications in an efficient and low-cost manner.

Expanding application of the Wiggers diagram to teach cardiovascular physiology

Dr. Carl Wiggers' careful observations have provided a meaningful resource for students to learn how the heart works. Throughout the many years from his initial reports, the Wiggers diagram has been used, in various degrees of complexity, as a fundamental tool for cardiovascular instruction. Often, the various electrical and mechanical plots are the novice learner's first exposure to simulated data. As the various temporal relationships throughout a heartbeat could simply be memorized, the challenge for the cardiovascular instructor is to engage the learner so the underlying mechanisms governing the changing electrical and mechanical events are truly understood. Based on experience, we suggest some additions to the Wiggers diagram that are not commonly used to enhance cardiovascular pedagogy. For example, these additions could be, but are not limited to, introducing the concept of energy waves and their role in influencing pressure and flow in health and disease. Also, integrating concepts of exercise physiology, and the differences in cardiac function and hemodynamics between an elite athlete and normal subject, can have a profound impact on student engagement. In describing the relationship between electrical and mechanical events, the instructor may find the introduction of premature ventricular contractions as a useful tool to further understanding of this important principle. It is our hope that these examples can aid cardiovascular instructors to engage their learners and promote fundamental understanding at the expense of simple memorization.

Assessment of systolic and diastolic function in asymptomatic subjects using ambulatory monitoring with acoustic cardiography

BACKGROUND

Adequately recording diastolic heart sounds and systolic time intervals over longer periods is difficult. Thus, information on the circadian variation of these parameters in an ambulatory population is lacking. Moreover, age-related changes in the prevalence of diastolic heart sounds and measurements of systolic time intervals in an asymptomatic population have not been studied in continuous recordings.

HYPOTHESIS

Diastolic heart sounds and systolic time intervals will have age and circadian variations that reflect known changes in cardiac function due to aging and circadian rhythms.

METHODS

We studied 128 asymptomatic subjects wearing an ambulatory monitor with acoustic cardiography. The recording spanned a mean duration of 14 hours, including sleep. Data were analyzed for the presence of third (S3) and fourth (S4) heart sounds and for systolic time intervals.

RESULTS

In these asymptomatic subjects, S3 was significantly more prevalent in those age <40 years than in those age >40 years, and significantly more pronounced during sleep in the younger group. Also, S4 was significantly more prevalent in those age >40 years and significantly more pronounced during sleep in those age >40 years. In contrast, time intervals reflecting systolic function showed less circadian variation and less worsening with age.

CONCLUSIONS

The nocturnal increase of S4 in the elderly reflects diastolic impairment-likely a result of changes in diastolic filling patterns with increasing age. An S3 after the age of 40 is a relatively uncommon finding and therefore should be a specific sign of cardiac disease. Continuous monitoring of diastolic heart sounds and systolic time intervals is possible using acoustic cardiography.

Physiology of the Third Heart Sound: Novel Insights from Tissue Doppler Imaging

BACKGROUND

The third heart sound (S(3)) is thought to be caused by the abrupt deceleration of left ventricular (LV) inflow during early diastole, increased LV filling pressures, and decreased LV compliance. We sought to determine whether the ratio of early mitral inflow velocity to diastolic velocity of the mitral annulus (E/E') could confirm the proposed mechanism of the S(3).

METHODS

A total of 90 subjects underwent phonocardiography, echocardiography, tissue Doppler imaging, and left-sided heart catheterization.

RESULTS

Phonocardiography detected an S(3) in 21 patients (23%). Subjects with an S(3) had lower ejection fraction (P = .0006) and increased E deceleration rate (P < .0001), E/E' (P < .0001) and filling pressures (P < .0001). The phonocardiographic S(3) confidence score correlated with E/E' (r = 0.46; P < .0001) and E deceleration rate (r = 0.43, P = .0001). Of the echocardiographic variables, only E/E' was independently associated with the S(3) confidence score (P = .009), independently of invasively determined LV filling pressures (P = .001).

CONCLUSIONS

The most important determinants of the pathologic S(3) are an increased deceleration rate of early mitral inflow, elevated LV filling pressures, and abnormal compliance of the myocardium as measured by tissue Doppler imaging.

Diagnostic characteristics of combining phonocardiographic third heart sound and systolic time intervals for the prediction of left ventricular dysfunction

BACKGROUND

The third heart sound (S3) and systolic time intervals (STIs) are validated clinical indicators of left ventricular (LV) dysfunction. We investigated the test characteristics of a combined score summarizing S3 and STI results for predicting LV dysfunction.

METHODS AND RESULTS

A total of 81 adults underwent computerized phonelectrocardiography for S3 and STI (Audicor, Inovise Medical Inc), cardiac catheterization for LV end-diastolic pressure (LVEDP), echocardiography for LV ejection fraction (LVEF), and B-type natriuretic peptide (BNP) testing. LV dysfunction was defined as both an LVEDP >15 mm Hg and LVEF <50%. The STI measured was the electromechanical activation time (EMAT) divided by LV systolic time (LVST). Z-scores for the S3 confidence score and EMAT/LVST were summed to generate the LV dysfunction index. The LV dysfunction index had a correlation coefficient of 0.38 for LVEDP (P = .0003), -0.53 for LVEF (P < .0001), and 0.35 for BNP (P = .0008). This index had a receiver operative curve c-statistic of 0.89 for diagnosis of LV dysfunction; a cutoff >1.87 yielded 72% sensitivity, 92% specificity, 9.0 positive likelihood ratio, and 88% accuracy.

CONCLUSIONS

In this preliminary study, the LV dysfunction index combined S3 and STI data from noninvasive electrophonocardiography, and yielded superior test characteristics compared to the individual tests for the diagnosis of LV dysfunction.

Clinical diagnosis of left ventricular dilatation and dysfunction in the age of technology

BACKGROUND

The diagnostic process has become increasingly dependent on instrumental and laboratory investigation.

AIM

To evaluate the accuracy of symptoms and signs in identifying left ventricular (LV) dilatation and/or systolic dysfunction.

METHODS

A group of 100 patients in stable clinical condition and scheduled for cardiac magnetic resonance imaging was prospectively examined by two cardiologists, who were unaware of the individual patient's condition. Patients were interviewed and underwent physical examination.

RESULTS

Several symptoms and signs were associated with LV dilatation and systolic dysfunction at univariate analysis. Using multiple logistic regression, a mitral systolic murmur, a laterally displaced LV impulse, orthopnoea and hepatomegaly were all independent predictors of LV dilatation (end-diastolic volume >or=110 ml/m(2)) (p<0.0001) and LV dysfunction (ejection fraction <45%) (p<0.0001). The combination of the above variables correctly identified 79% of patients with LV dilatation (sensitivity 51%, specificity 92%), and 82% of patients with LV dysfunction (sensitivity 68%, specificity 90%). Considering LV dilatation and dysfunction, 77% of patients were correctly identified after history alone (kappa=0.13), 84% after LV impulse examination (kappa=0.55) and 86% after cardiac auscultation (kappa=0.58).

CONCLUSION

Symptoms and signs predict LV dilatation and/or dysfunction with fair sensitivity and excellent specificity.

Third heart sound: genesis and clinical importance

Auscultation of third heart sound has been performed for more than a century, an interest that not only persists today, but also has experienced renewed emphasis. Sophisticated study of the third heart sound by current investigative techniques has underscored the value of clinical detection with the time-honored stethoscope. This review re-examines the mechanisms of genesis of third heart sound in regard to the hemodynamic and echocardiographic aspects, and its clinical importance.

Usefulness of the third heart sound in predicting an elevated level of B-type natriuretic peptide

Third heart sounds were sought in 100 consecutive outpatients who had B-type natriuretic peptide (BNP) levels measured within 8 hours. Mean BNP levels were significantly higher in those with a third heart sound. The presence of a third heart sound was 41% sensitive and 97% specific for elevated BNP levels.

Pathophysiologic determinants of third heart sounds: a prospective clinical and Doppler echocardiographic study

PURPOSE

We sought to determine the importance of a third heart sound (S(3)) and its relation to hemodynamic and valvular dysfunction.

SUBJECTS AND METHODS

We prospectively enrolled 580 patients who had isolated valvular regurgitation (mitral, n = 299; aortic, n = 121) or primary left ventricular dysfunction with or without functional mitral regurgitation (n = 160). We analyzed the associations between the clinical finding of an audible S(3) (as noted in routine clinical practice by internal medicine physicians) and hemodynamic alterations measured by comprehensive quantitative Doppler echocardiography.

RESULTS

S(3) was more prevalent in patients with primary left ventricular dysfunction (46%, n = 73) than in organic mitral (16%, n = 47) or aortic (12%, n = 14) regurgitation (P <0.001). Patients with an S(3) were more likely to have class III-IV symptoms (55% [74 of 137] vs. 18% [80 of 443] of those without an S(3), P <0.001) and had a higher mean [+/- SD] pulmonary pressure (55 +/- 15 vs. 41 +/- 11 mm Hg, P <0.001). An S(3) was also related to a higher early filling velocity due to a greater filling volume, restrictive filling, or both. An S(3) was a marker of severe regurgitation (regurgitant fraction > or =40%) in patients with primary left ventricular dysfunction (odds ratio [OR] = 2.4; 95% confidence interval [CI]: 1.1 to 5.5), mitral regurgitation (OR = 17; 95% CI: 5.8 to 52), and aortic regurgitation (OR = 7.1; 95% CI: 1.8-28). An S(3) was also associated with restrictive filling in primary left ventricular dysfunction (OR = 3.0; 95% CI, 1.6 to 5.9), marked dilatation in mitral regurgitation (OR = 20; 95% CI: 6.8 to 58), and an ejection fraction (<50%) in aortic regurgitation (OR = 19; 95% CI: 6.0 to 62).

CONCLUSION

An audible S(3) is an important clinical finding, indicating severe hemodynamic alterations, and should lead to a comprehensive assessment and consideration of vigorous medical or surgical treatment.

Prediction of the Third and Fourth Heart Sounds by Doppler Echocardiography

Doppler echocardiographic variables were sought for predicting the third and fourth heart sounds, as documented by phonocardiography. Phonocardiographic recordings of gallop sounds and Doppler echocardiographic investigations of mitral inflow and pulmonary venous flow were evaluated in 85 subjects by discriminant and multiple regression analysis. Of 85 subjects 47% had a third sound and 72% a fourth sound, evaluated by phonocardiography. A correct identification of 85% subjects with, and 82% without, the third sound was possible by discriminant analysis using the ratio of peak early diastolic to peak atrial mitral flow velocity (FV), the interval from peak ECG R wave to peak early diastolic mitral FV, and the early diastolic mitral FV deceleration time. At the observed prevalence of the third heart sound (47%), the predictive positive value was 81% and the predictive negative value was 86%. A correct identification of 72% of the subjects with, and 83% without, a fourth sound was possible by discriminant analysis using the ratio of peak early diastolic to peak atrial mitral FV, the interval between the end of atrial mitral FV and the peak ECG R wave, and the duration of pulmonary venous reverse FV at atrial systole. At the observed prevalence of the fourth heart sound (72%) the predictive positive value was 92% and the predictive negative value was 54%. By multiple regression analysis, up to 50% of the amplitude of both gallop sounds was predictable by a combination of Doppler echocardiographic variables.

Newer Doppler measures of left ventricular diastolic function

Left ventricular (LV) diastolic dysfunction is an important cause of heart failure, and recent advances in the application of Doppler techniques allow a semiquantitative assessment of LV diastolic performance. This review discusses the use of Doppler echocardiography in the comprehensive assessment of LV diastolic function and performance in terms of the normal mitral and pulmonary venous flow profiles, their physiologic basis, and alterations in diseased states. There is also a discussion on the newer aspects of mitral flows such as relative durations of mitral A and pulmonary vein AR waves, E- and A- wave propagation inside the LV with their hemodynamic correlates, and derivation of ventricular dP/dt and Tau from the mitral regurgitation velocity profile. Analysis of these flow profiles and the other Doppler measures alluded to above allow one to make a fairly precise hemodynamic assessment of a patient in terms of left atrial pressure, LV relaxation and stiffness and the profile of LV diastolic pressure in terms of pre- 'a' wave and 'a' wave pressures and ventricular end-diastolic pressure.