Functional murmur

Abstract: Background Left ventricular false tendons (LVFTs) are fibrous or fibromuscular bands stretching across the left ventricle (LV) from the ventricular septum to the papillary muscle or LV free wall but not connecting, like the chordae tendinae, to the mitral leaflet. LVFTs have become the focus of studies and discussions since the advent of echocardiography. Materials and Methods We prospectively studied the prevalence of LVFTs by two-dimensional echocardiography in 476 infants and children referred to our institute for cardiac evaluation and cardiology workup. We also studied the morphology and histopathology of LVFTs in 68 congenital heart disease specimens and in 20 piglet hearts. The literature was reviewed and the clinical significance of LVFTs was discussed. Results LVFTs of varying size and different location were detected in 371 (77.9%) of 476 infants and children studied, in 42 (61.8%) of 68 congenital heart disease specimens, and in 19 (95.0%) of 20 piglet hearts. Of the 75 LVFTs from the congenital heart disease specimens, 33 (44.4%) were fibrous type, measuring less than 1.4 mm; 38 (50.7%) were fibromuscular type, 1.5–2.4 mm; and 4 (5.3%) were muscular type, 2.5 mm or more in diameter. Of the 33 LVFTs from the piglet hearts, 23 (69.7%) and 10 (30.3%) were fibrous and fibromuscular, respectively, and none (0.0%) was muscular. Conclusions LVFTs were detected partially or completely by modified two-dimensional echocardiography in both normal and abnormal hearts. LVFTs is a useful anatomical landmark of LV for the differentiation of morphological LV and right ventricle in segmental analysis of congenital heart disease. LVFTs are a cause of functional murmur. No pressure gradient was noted in the mid-LV or outflow tract. LVFTs could be a contributory factor in the generation of dysrhythmias during LV catheterization studies. LVFTs were more easily identifiable in neonates and young age patients because of a better delineation of images in echocardiography.

Abstract: Many normal children have heart murmurs, but most children do not have heart disease. An appropriate history and a properly conducted physical examination can identify children at increased risk for significant heart disease. Pathologic causes of systolic murmurs include atrial and ventricular septal defects, pulmonary or aortic outflow tract abnormalities, and patent ductus arteriosus. An atrial septal defect is often confused with a functional murmur, but the conditions can usually be differentiated based on specific physical findings. Characteristics of pathologic murmurs include a sound level of grade 3 or louder, a diastolic murmur or an increase in intensity when the patient is standing. Most children with any of these findings should be referred to a pediatric cardiologist.

Abstract: Background: For many years, cardiac auscultation has been the only available method for distinguishing between functional and organic murmurs; however, a more reliable differential diagnosis can now be achieved with Doppler echocardiography. The question remains as to whether a Doppler echocardiogram needs to be routinely recorded in the presence of a heart murmur or whether the auscultatory diagnosis of a functional murmur is sufficient. Hypotltesis: This prospective study attempts to answer this important question at a time when medical costs have to be curbed. Methods: The three cardiologists involved in this study saw 516 new patients in their private practice over a 10-month period; of these, 321 (63.6%) underwent Doppler echocardiography. All patients underwent careful auscultation prior to echocardiography. At the end of their examinations, the cardiologists noted whether they considered the murmur to be of functional or organic origin. Minimal mitral or aortic regurgitations of short duration and low velocity occurring on non-thickened valves were considered functional. Results: The results for cardiac auscultation and Doppler echocardiography were considered to be concordant, that is, both techniques diagnosed either a functional or organic murmur in 250 of 321 patients (77.9%). The results for cardiac auscultation and Doppler echocardiography showed a major discordance in just six cases (1.9%). All were mitral regurgitations of moderate severity. Conclusion: The prevalence of cardiac murmurs in the general population is very high. As echocardiography currently represents a significant proportion of cardiac medical expenditure, it would be wise to limit the use of this technique to essential indications. This study confirms that both cardiac auscultation and Doppler echocardiography possess important limitations. Nevertheless, it also shows that well-trained cardiologists can identify the vast majority of functional murmurs on auscultation. Better training of nonspecialist physicians in cardiac auscultation may help in containing medical expenses.

Abstract: In order to evaluate the clinical significance of the markedly protruding interventricular septum into the left ventricular (LV) cavity (sigmoid septum), we performed non-invasive studies including amyl nitrite (AN) inhalation in 21 patients (pts) with two-dimensional echocardiographic (2DE) documentations. LV outflow tract (LVOT) obstruction was determined by the presence at least three of the following findings at rest or during AN inhalation: 1) a loud apical ejection systolic murmur (ESM), 2) a midsystolic dip in the carotid pulse, 3) systolic anterior motion (SAM) of the mitral valve (MV) or chordae tendineae, and 4) systolic semiclosure of the aortic valve (AV). The 21 pts were subdivided into six pts (group I) with resting (two pts) or provocative (four) obstruction, and 15 pts (group II) without obstruction. Their ages ranged from 40 to 85 years with an average of 65. No pt had evidence of hypertrophic cardiomyopathy. Results were as follows: In five pts of group I a long ESM with a mid-systolic peak was recorded near the apex. After AN inhalation, this murmur was markedly intensified. On the contrary, all pts of group II had a short and early systolic murmur, which was not markedly intensified by AN. In contrast to group II, group I pts had a significantly smaller LV end-diastolic dimension, a smaller LVOT dimension, higher percent thickening of the LV posterior wall, higher fractional shortening and decreased aorto septal angle (the angle between the anterior aortic wall and the interventricular septum by 2DE). On 2DE, each pt of group I showed significant narrowing between the protruded septum and the hypercontractile LV posterior wall with the papillary muscle. Anteriorly shifted chordae tendineae noted as the SAM on the M-mode echocardiogram might also play an important role on the genesis of obstruction. The signs of LVOT obstruction at rest disappeared following oral administration of propranolol in two pts of group I. These observations suggested that LVOT obstruction might occur in some pts with sigmoid septum and the hypercontractile state, and that a systolic murmur observed in this condition should be differentiated from a functional murmur in the aged or a systolic murmur in hypertrophic obstructive cardiomyopathy.