Showing papers by "Roland E. Schmieder published in 1986"

Left ventricular hypertrophy. A cardiovascular risk factor in essential hypertension.

Abstract: The heart adapts to increasing afterload, such as that which occurs in arterial hypertension, with an increase in wall thickness in order to bring wall stress back to normal. As a consequence, concentric left ventricular hypertrophy ensues. Hypertension as well as advancing age has been shown to be associated with an increase in posterior wall thickness. Accordingly, the prevalence of left ventricular hypertrophy becomes very high in the elderly and may occur in more than 50% of elderly hypertensive patients. Left ventricular hypertrophy is not merely a physiological process serving to compensate for the increased afterload. The Framingham study has indicated that patients with left ventricular hypertrophy are at an increased risk of sudden death and other cardiovascular morbidity and mortality. The risk for sudden death is 5 to 6 times higher in patients with left ventricular hypertrophy than in those without, regardless of levels of arterial pressure. By Holter monitoring of these patients it has been shown that those with left ventricular hypertrophy have a prevalence of premature ventricular contractions that is 40 to 50 times higher than those patients without left ventricular hypertrophy. In addition, patients with left ventricular hypertrophy rated substantially higher with regard to Lown’s classes than those without. These data indicate that left ventricular hypertrophy is common, particularly in the elderly, and predisposes to ventricular ectopy, higher grade arrhythmias, and sudden death. Clearly, these considerations have to be taken into account when selecting antihypertensive therapy inasmuch as hypokalaemia, hypomagnesaemia, and other electrolyte shifts predisposing to ventricular arrhythmias must be scrupulously avoided.

Use of diuretic agents in obese or black patients with systemic hypertension.

Abstract: Any increase in arterial pressure is the result of either an increase in cardiac output, an increase in total peripheral resistance or a combination of the two. Hypertension is not a homogeneous disease, however, and different mechanisms may be operative during the life span of the patient. Hypertension in the young, nonobese patient is usually hemodynamically characterized by high cardiac output, normal to slightly contracted intravascular volume and numerically normal total peripheral resistance. In contrast, hypertension in the middle-aged or elderly patient is usually hemodynamically characterized by normal to low cardiac output, contracted intravascular volume and high total peripheral resistance. Two further subgroups of hypertensive patients can be identified: obese patients, whose hypertension is characterized by high cardiac output, expanded intravascular volume and normal or low total peripheral resistance, and black patients, whose hemodynamic and fluid volume findings are similar to those of their white counterparts, but who tend to have lower heart rates and greater responsiveness to intravascular volume depletion than white hypertensive subjects. A rational therapeutic approach to essential hypertension should take into account these variable pathophysiologic features. Thiazide diuretics continue to be appropriate and generally well-tolerated choices for initial antihypertensive therapy in obese or in black patients. Many obese patients or black patients, however, are likely to develop early left ventricular (LV) hypertrophy. Patients with electrocardiographic or echocardiographic evidence of LV hypertrophy have been shown to have a higher prevalence of ventricular ectopic activity and to be at higher risk of sudden death than patients without evidence of LV hypertrophy. Some studies have shown that obese patients and black patients are at higher risk of developing LV hypertrophy. Thiazide diuretic-induced hypokalemia may exacerbate ventricular ectopic activity and cause more serious arrhythmias. Potassium depletion should, therefore, be prevented in patients with evidence of the LV hypertrophy. If thiazide diuretics are used in this context, the addition of a potassium sparing agent, such as amiloride, is recommended.

Environmental factors as a risk for future hypertension

Abstract: A review of the literature indicates that several factors have been purported to increase the risk for the development of arterial hypertension: family history, age, sex, race, nutritional factors, salt intake, obesity, various chemical agents, traffic noise, occupational stress, socioeconomic status and social stress. However, it is not known whether these are really independent risk factors for hypertension. We point out that these factors are related to each other and that they differ with regard to their impact on the pathogenesis of essential hypertension. In particular, a hyper-responsiveness of blood pressure to different stimuli, reflecting an overreactivity of the sympathetic nervous system, appears to play a central role in the pathogenesis of hypertension. Thus, the haemodynamic response to provocative stress tests may enable us to identify individuals at high risk for future hypertension.