Hypercontractile cardiac states simulating hypertrophic cardiomyopathy.

Abstract

SUMMARY Hypertrophic cardiomyopathy (HCM) or idiopathic hypertrophic subaortic stenosis (IHSS) has been defined as an autosomal dominant myocardial disease characterized by specific physical findings, echocardiographic features, asymmetric septal hypertrophy and disordered myocardial architecture. Echocardiographic and scintiphotographic studies failed to reveal evidence of asymmetric septal hypertrophy in four patients with systolic anterior movement of the mitral valve and the typical auscultatory and HYPERTROPHIC CARDIOMYOPATHY (HCM) or idiopathic hypertrophic subaortic stenosis (IHSS) has been defined by certain physical findings," 2 and characteristic hemodynamic," 2 angiographicl'3 and pathologic abnormalities.1' 2, 4-7 Echocardiography provides a valuable noninvasive means of recognizing HCM and, in many institutions, has replaced catheterization as a means of confirming clinical diagnoses. Major echocardiographic features of HCM include abnormal thickness8" of the interventricular septum which is asymmetrically hypertrophied relative to the left ventricular free wall,9-1" systolic anterior movement of the mitral valve'2, '3 and reduction of systolic septal thickening and amplitude of systolic septal excursion.8 Myocardial imaging with a radioactive tracer, thallium 201,'4 has also demonstrated the presence of disproportionate septal thickness and appears to be an additional noninvasive means of diagnosing HCM, particularly when adequate echocardiographic definition of the interventricular septum is not feasible technically.A unified concept of hypertrophic cardiomyopathy as an autosomal dominant myocardial disease characterized by asymmetric septal hypertrophy and disordered myocardial architecture has been proposed.2'" This paper reports four patients with typical physical findings of HCM and echocardiographic documentation of systolic anterior movement of the mitral valve in whom a combination of echocardiographic and scintiphotographic studies and, in one instance, postmortem examination failed to demonstrate asymmetric septal hypertrophy. Systolic anterior movement of the mitral valve and the auscultatory and peripheral pulse abnormalities characteristic of HCM do not therefore appear to be specific for the autosomal dominant myocardial dis- ease characterized by asymmetric septal hypertrophy and abnormal septal histology. Materials and Methods Echocardiographic StudiesThe echocardiographic examinations were performed with a Smith-Kline Ekoline 20 A Ultrasonoscope using a 0.5 inch diameter, 2.25 MHz transducer focused at 7.5 cm. The echocardiograms were recorded on a Cambridge strip chart recorder or Honeywell direct writing recorder (patient 3). Standard techniques were employed to record tracings from the anterior and posterior mitral leaflets and from the septum and posterior wall just below the mitral leaflets. Systolic and end-diastolic cavity dimensions and septal and posterior wall thicknesses were measured at this level,"5 and the ratio of end-diastolic septal to posterior wall thickness calc...

Quantitative left ventricular contractility analysis under stress: a new practical approach in follow-up of hypertensive patients

“…LV hypercontractility in the earlier stage of hypertensive heart disease is detectable at rest and under stress in the outpatient setting. [7][8][9][10][11][12]32,58 Recently, it has been demonstrated by comprehensive imaging studies, that LV contractility parameters are blunted by stress in the HFPEF group. 59,60 These findings have consistently correlated with poor prognostic factors of low EF and larger volume under stress.…”

“…Excessive sympathetic stimulation and LV hypercontractile state possibly are important in the clinical presentation of hypertension. 10,11 In a study conducted in patients with findings of chest pain and normal coronary arteries, wall motion analysis has shown a LV hypercontractile response to sympathetic stimulation. 12 The same study showed that hypertension was more frequent in patients with hypercontractile response to stress compared with those without hypercontractility.…”

Transient left ventricular dysfunction (tako-tsubo phenomenon): Findings and potential pathophysiological mechanisms

“…This left ventricular geometric configuration is predominantly found in elderly, hypertensive women. In the setting of adrenergic stimulation and/or hypovolemia, dynamic left ventricular outflow-tract obstruction may become manifest (75,76). As a consequence of obstruction, apical and anterior wall stress and left ventricular filling pressure increase, while systemic blood pressure decreases.…”

Mechanistic Heterogeneity in Contractile Properties of α-Tropomyosin (TPM1) Mutants Associated with Inherited Cardiomyopathies

“…E40K and E54K are DCM-causing mutants that decrease Ca 2ϩ sensitivity in ATPase assays and lower tension at high Ca 2ϩ concentrations in myofiber experiments, whereas the HCM-causing mutants D175N and E180G show opposite changes to the DCM mutants (19). Beyond these binary tendencies, the detailed causes of hypercontractility of HCM-causing mutants (20) and hypocontractility of DCM-causing mutants (21) are only partially understood. Although multiple sources of mammalian Tm and other sarcomeric proteins have been used previously (22,23), we focus here on the human cardiac sarcomeric proteins.…”