Genesis of Still's murmurs: a controlled Doppler echocardiographic study.

Abstract

Objective-The origin of innocent systolic murmurs is uncertain. This study was designed to evaluate the relative contribution in the same subjects of the main factors implicated in the genesis of vibratory innocent systolic murmursthat is, the presence of left ventricular bands and increased left ventricular flow indices-and to examine evidence for turbulence in relation to these findings.Patients-40 children with innocent systolic murmurs and 40 paired controls without murmurs were matched for age and body surface area.Design-These subjects were examined prospectively by cross sectional echocardiography with pulsed and continuous wave Doppler and colour flow mapping.Setting-A tertiary referral centre for paediatric cardiology.Results-Left ventricular bands were significantly more prevalent in patients with innocent murmurs (70%) than in controls (48%) but only if apical bands were included (p = 0-039). Cases had significantly higher aortic peak flow velocities (p < 0-001), flow integrals (p = 0001), and stroke volumes (p = 0-014), and significantly lower heart rates (p = 0 033) than controls. There were no significant differences between cases and controls in mean aortic diameter, cardiac output, or ejection fraction. There was no evidence of turbulence in the left ventricle or outflow tract in any individual but curvilinear periodic vibrations and audible "whoops" were detected in the left ventricle by pulsed wave Doppler echocardiography. These were significantly more common in cases than controls (p < 0-01) but were not related to the presence of bands.Conclusions-Innocent systolic murmurs were unrelated to aortic size but they were strongly associated with higher aortic flow volume and velocity, with relative bradycardia, and with evidence of vibratory phenomena in the left ventricle. Left ventricular flow characteristics have also been investigated as a possible cause of the murmur. Schwarz et al reported that the peak velocities in the ascending and descending aorta were significantly greater in children with innocent murmurs and ascribed this to a narrower aortic diameter in this group compared with children without murmurs.7 These findings were confirmed by Sholler and colleagues8 but not by Van Oort et al who found no difference in the peak velocity, acceleration, or spectral width of the aortic flow signal between children with innocent murmurs and children without.9 There is currently no consensus on the origin of the musical murmur in structurally normal hearts.This study was designed to determine the prevalence of bands, the presence of turbulence about the bands and in the left ventricular outflow tract, and left ventricular flow characteristics and systolic function in children with innocent murmurs and without. Patients and methodsWe studied 40

Epidemiology of Left Ventricular False Tendons: Clinical Correlates in the Framingham Heart Study

“…LVFTs have been associated with clinical,11,13,24,27-32 electrocardiographic11,14,20,22,30,33-37 and echocardiographic29,38,39 abnormalities. Therefore, we examined the association of LVFTs with all-cause mortality on follow-up.…”

“…These include an increased prevalence of precordial murmurs,11,13,24,27-32 repolarization abnormalities on the resting electrocardiogram,33,34 pre-excitation,30 ventricular arrhythmias,11,14,20,22,35-37 mitral regurgitation,38 and a dilated left ventricle 29,39. Most of these clinical associations have been described, however, only in small clinical case series.…”

Basic Study and Clinical Implications of Left Ventricular False Tendon. Is it Associated With Innocent Murmur in Children or Heart Disease?

“…As in this study, the most widely accepted association is with innocent murmur in children. [16][17][18] This murmur has been related to increased velocity in the aorta 28 ; in our study, the presence of FT was not a confounding factor but rather indicated that this velocity is slower. In fact, the movement produced by blood outflow may produce vibratory movement in the FT that causes the murmur and reduces blood flow at the aortic velocity.…”

“…The percentage of FT visualization in humans has been rising with technical improvements: the earliest studies report rates of 0.5% whereas current investigations have achieved up to 78%. [7][8][9][10][11][12][15][16][17] False tendon has been related to clinical signs, such as innocent murmur, [16][17][18] conduction and heart rate abnormalities, 19,20 cavitary thrombi, 21 and even infections, 22 although there is no consensus on the implication of FT in human physiology or disease. Its morphogenesis and embryonic origin are not well known, and prenatal imaging has been rare, with only a few reports of the condition observed during the fetal period.…”

The preoperative management of the child with a heart murmur

“…In these studies the murmur seemed to be related to higher peak velocities in the ascending and descending aorta caused in turn by a narrower aortic diameter (Schwartz et al 1986;Sholler, CeIemajer & Wright 1987). Or the murmur may be related to higher aortic flow volume and velocity but not caused by a smaller aortic size (Gardiner & Joffe 1991). It may be that turbulence in the aortic root is responsible or that in hearts with some structural abnormality, vibration of intracardiac structures causes the murmur (Stein & Sabbah 1977;Stein et al 1982;Sheikh et al 1984;Pennestri et al 1989).…”