Prevalence of late ventricular potentials in hypertensive patients

The heart, kidney, and brain as target organs in hypertension

The heart, kidney, brain, and arterial blood vessels are prime targets of hypertensive damage. Uncontrolled hypertension accelerates the damage to these organs and results in eventual organ failure and cardiovascular death and disability. Current guidelines for the appropriate treatment and control of hypertension requires an assessment of the presence of target organ damage. When present, evidence of target organ damage determines the urgency and intensity of drug treatment and may also dictate the choice of initial antihypertensive drug class. Thus, evaluation of persons with suspected or established hypertension must include a meticulous search for evidence of target organ damage. Fortunately, treatment with all antihypertensive medications that results in significant BP reductions also reduces fatal and nonfatal hypertensive complications and significantly slows down the progression to organ failure. Because of the important role that adverse activation of the renin-angiotensin-aldosterone system plays in target organ damage, drugs that antagonize this system have provided consistent and compelling proof of organ protection in both primary and secondary prevention of adverse outcomes. The challenge now is to use these and all other antihypertensive agents effectively to control BP to target levels in patients with hypertension. Continued emphasis on the adoption of lifestyle changes for prevention of hypertension in the first place or as adjunctive therapy in hypertensive patients is essential.

Ventricular arrhythmias in adult aortic stenosis: prevalence, mechanisms, and clinical relevance

With the longer life expectancy of the population, calcific aortic stenosis has become a common cardiac problem in the elderly. When patients with moderate to severe aortic stenosis become symptomatic, the prognosis is usually poor in absence of valve replacement and sudden death is a feared complication. It has been hypothesized that malignant ventricular arrhythmias could be responsible for the high incidence of sudden death in symptomatic patients with aortic stenosis. The purpose of this review is to analyze the prevalence, the electrophysiologic mechanisms, and the possible role of ventricular arrhythmias in the development of symptoms and in the outcome of adult subjects with aortic stenosis.

Cardiac arrhythmias and left ventricular hypertrophy in systemic hypertension and their influences on prognosis

Left ventricular hypertrophy (LVH) is the adaptative mechanism of the heart to systolic overload of the left ventricle. Nevertheless, LVH plays a role in some complications, such as cardiac arrhythmias. Patients with LVH are more likely to develop ventricular arrhythmias than the hypertensive population without LVH. Further, the relation between left ventricular mass and ventricular arrhythmias is graded and continuous. The arrhythmias described in hypertensive patients with LVH are usually isolated premature ventricular contractions. The presence of electrocardiographic criteria of LVH represents a risk of higher incidence of sudden death, especially in men. The risk is even greater in the presence of ventricular arrhythmias. The presence of late potentials has been recently characterized as more related to ventricular arrhythmias than LVH. Antihypertensive drugs that can reduce LVH also have a beneficial effect on cardiovascular morbility and mortality.

Study of late potentials and ventricular arrhythmias in hypertensive patients with normal electrocardiograms

INTRODUCTION

Although an increase in the occurrence of ventricular arrhythmias has been observed in hypertensive patients, some basic questions remain unresolved regarding the prevalence and the pathophysiology of these arrhythmias. The basic aims of this study were as follows: (1) to examine the incidence and severity of ventricular arrhythmias in a substantial number of hypertensive patients without electrocardiographic indications of hypertrophy; and (2) to examine the correlation between late potentials, hypertrophy, and ventricular arrhythmias in these patients.

MATERIALS AND METHODS

We studied 78 consecutive patients (31 men, 47 women), aged 60.5 +/- 7.8 years, with a history of hypertension but a normal electrocardiogram. All patients had an echocardiographic study, 24-hour ambulatory monitoring, exercise test, and signal-averaged electrocardiogram. The latter was analyzed using a 40- to 250-Hz filter and with a noise level < or = 0.3 microV.

RESULTS

Of the 78 patients studied, 21 (26.9%) had severe ventricular arrhythmias, while 57 (73.1%) had either no ventricular ectopics or sporadic isolated ventricular extrasystoles. Left ventricular hypertrophy, defined by echocardiography, was found in 58 patients (74.3%), of which 16 (27.58%) had severe ventricular arrhythmias. Five (25%) of the 20 patients without hypertrophy also had severe ventricular arrhythmias (P = NS). Ventricular late potentials were recorded in 19 (24.5%) of the 78 patients. Of these, 11 (57.89%) had severe arrhythmias, while of the 59 patients without late potentials 10 (16.94%) had severe ventricular ectopic activity.

CONCLUSIONS

In hypertensive patients without electrocardiographic signs of hypertrophy, the higher prevalence of ventricular arrhythmias does not appear to be related to left ventricular hypertrophy but is correlated with the existence of ventricular late potentials.