Cardiac and carotid structure in arterial hypertension and in hypertrophic cardiomyopathy

Hypertrophic and hypertensive hypertrophic cardiomyopathy--a true association?

The cardiomyopathies were previously defined as ''heart muscle diseases of unknown cause'' and were differentiated from specific heart muscle disease with known cause. With increasing understanding of etiology and pathogenesis, the difference between cardiomyopathy and specific heart muscle disease has become indistinct. The term specific cardiomyopathies are used to describe heart diseases that are associated with specific cardiac or systemic disorders. These were previously defined as specific heart muscle diseases. They included ischemic cardiomyopathy, valvular cardiomyopathy, hypertensive cardiomyopathy, inflammatory cardiomyopathy, metabolic cardiomyopathy, general system disease, muscular dystrophies, sensitivity and toxic reactions, and peripartal cardiomyopathy. The cardiomyopathies are therefore classified by the dominant pathophysiology or, if possible, by etiological/pathogenetic factors. Topol in 1985 described a syndrome called hypertensive hypertrophic cardiomyopathy that included severe concentric cardiac hypertrophy, a small left ventricular cavity, and supernormal indexes of systolic function without concurrent medical illness or ischemic heart disease. The aim of this review was to highlighted this syndrome from pathophysiological, clinical, diagnostical view and clear all the possible correlations with genetic, inflammatory, and other markers.

Impaired peripheral vasoconstriction in response to alpha-adrenergic stimulation in patients with idiopathic hypertrophic cardiomyopathy

Exercise hypotension has been documented in patients with hypertrophic cardiomyopathy (HCM). Some investigators reported that this is due to an inadequate increase of systemic vascular resistance during or after exercise. The aim of this study was to investigate the pathogenesis of limb vascular response abnormalities in patients with idiopathic HCM. Thirteen patients with HCM and 9 healthy controls were administered an endothelium-dependent dilator (acetylcholine), a direct smooth muscle dilator (nitroglycerin), an alpha-adrenergic stimulator (phenylephrine), and a beta-adrenergic stimulator (isoproterenol) by intra-arterial infusion. Peripheral vascular resistance was assessed by forearm plethysmography at rest and during each infusion to obtain the percentage change in vascular resistance. Isoproterenol, acetylcholine and nitroglycerin produced dose-related vasodilatation with no significant differences between HCM patients and healthy controls. The percentage increase in vascular resistance was significantly less in HCM patients than in healthy controls after phenylephrine infusions of 0.5 microg/min (155+/-38% vs 195+/-47%, mean+/-SD, p<0.05) and 1.0 microg/min (174+/-49% vs 238+/-65%, p<0.05). Vasoconstriction mediated by alpha-adrenergic receptors appeared to be impaired in the peripheral vasculature of patients with HCM.

Intima-media thickness of the carotid artery in hypertensive subjects and hypertrophic cardiomyopathy patients

While hypertension is known to cause left ventricular and vascular hypertrophy, the relationship between alterations of vascular and cardiac structures in patients with hypertrophic cardiomyopathy has not been fully clarified. We measured intima-media thickness of carotid arteries by ultrasonography in patients with hypertrophic cardiomyopathy (n = 16), normotensive subjects (n = 358), and hypertensive subjects (n = 386) in a cohort of 7940 male employees of a bus company. Our object was to determine whether vascular alteration occurs in hypertrophic cardiomyopathy similarly as in hypertension. Hypertrophic cardiomyopathy (wall thickness > or = 15 mm; asymmetrical hypertrophy without hypertension) was screened with family history and electrocardiography followed by echocardiography. The intima-media thickness in patients with hypertrophic cardiomyopathy (mean, 0.61 mm) did not differ from that of normotensive subjects (0.60 mm) but was significantly less than that of hypertensive subjects with left ventricular hypertrophy (wall thickness > or = 14 mm; n = 22; 0.73 mm). In a scatterplot of intima-media thickness versus interventricular septal thickness, these two parameters were significantly correlated in normotensives and hypertensives. The patients with hypertrophic cardiomyopathy distributed outside the 95% confidence range of the normotensive and hypertensive subjects. In summary, the increase in intima-media thickness of the carotid artery paralleled left ventricular hypertrophy in normotensive and hypertensive subjects. Patients with hypertrophic cardiomyopathy had a normal intima-media thickness regardless of the hypertrophied left ventricle. Thus, information on intima-media thickness may be useful in differentiating hypertensive left ventricular hypertrophy from hypertrophic cardiomyopathy.