The effects on cardiac arrhythmias of antihypertensive therapy causing regression of left ventricular hypertrophy

Is hypertensive left ventricular hypertrophy a cause of sustained ventricular arrhythmias in humans?

Sudden cardiac death (SCD) is most commonly secondary to sustained ventricular arrhythmias (VAs). This review aimed to evaluate if left ventricular hypertrophy (LVH) secondary to systemic hypertension in humans is an isolated risk factor for ventricular arrhythmogenesis. Animal models of hypertensive LVH have shown changes in ion channel function and distribution, gap junction re-distribution and fibrotic deposition. Clinical data has consistently exhibited an increase in prevalence and complexity of non-sustained VAs on electrocardiographic monitoring. However, there is a dearth of trials suggesting progression to sustained VAs and SCD, with extrapolations being confounded by presence of co-existent asymptomatic coronary artery disease (CAD). Putatively, this lack of data may be due to the presence of more homogenous distribution of pathophysiological changes seen in those with hypertensive LVH versus known pro-arrhythmic conditions such as HCM and myocardial infarction. The overall impression is that sustained VAs in the context of hypertensive LVH are most likely to be precipitated by other causes such as CAD or electrolyte disturbance.

Hypertension and Arrhythmias

Hypertension is the most common cardiovascular risk factor and underlies heart failure, coronary artery disease, stroke, and chronic kidney disease. Hypertensive heart disease can manifest as cardiac arrhythmias. Supraventricular and ventricular arrhythmias may occur in the hypertensive patients. Atrial fibrillation and hypertension contribute to an increased risk of stroke. Some antihypertensive drugs predispose to electrolyte abnormalities, which may result in atrial and ventricular arrhythmias. A multipronged strategy involving appropriate screening, aggressive lifestyle modifications, and optimal pharmacotherapy can result in improved blood pressure control and prevent the onset or delay progression of heart failure, coronary artery disease, and cardiac arrhythmias.

Hypertension and cardiac arrhythmias: a consensus document from the European Heart Rhythm Association (EHRA) and ESC Council on Hypertension, endorsed by the Heart Rhythm Society (HRS), Asia-Pacific Heart Rhythm Society (APHRS) and Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología (SOLEACE)

Hypertension is a common cardiovascular risk factor leading to heart failure (HF), coronary artery disease, stroke, peripheral artery disease and chronic renal insufficiency. Hypertensive heart disease can manifest as many cardiac arrhythmias, most commonly being atrial fibrillation (AF). Both supraventricular and ventricular arrhythmias may occur in hypertensive patients, especially in those with left ventricular hypertrophy (LVH) or HF. Also, some of the antihypertensive drugs commonly used to reduce blood pressure, such as thiazide diuretics, may result in electrolyte abnormalities (e.g. hypokalaemia, hypomagnesemia), further contributing to arrhythmias, whereas effective control of blood pressure may prevent the development of the arrhythmias such as AF. In recognizing this close relationship between hypertension and arrhythmias, the European Heart Rhythm Association (EHRA) and the European Society of Cardiology (ESC) Council on Hypertension convened a Task Force, with representation from the Heart Rhythm Society (HRS), Asia-Pacific Heart Rhythm Society (APHRS), and Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología (SOLEACE), with the remit to comprehensively review the available evidence to publish a joint consensus document on hypertension and cardiac arrhythmias, and to provide up-to-date consensus recommendations for use in clinical practice. The ultimate judgment regarding care of a particular patient must be made by the healthcare provider and the patient in light of all of the circumstances presented by that patient.

Losartan controlled blood pressure and reduced left ventricular hypertrophy but did not alter arrhythmias in hypertensive men with preserved systolic function

The effect of antihypertensive therapy on arrhythmias is controversial. An initial study in patients with chronic heart failure indicated that losartan, an angiotensin II receptor antagonist, may possess antiarrhythmic properties. However, the effect of AT1 receptor antagonists on arrhythmias of subjects with good systolic function has never been evaluated. Thirty-nine men with primary hypertension (18 without left ventricular hypertrophy [LVH], and 21 with LVH, aged 48.2 +/-8.6 and 50.5 +/-6.0 years, respectively), 15 healthy normotensive subjects (47.9 +/-8.5 years), and 14 highly trained athletes (34.1 +/-1.6 years) were studied. Transthoracic echocardiography and 24-hour Holter ambulatory monitoring were performed at baseline (without treatment). Hypertensive patients underwent the same examinations after 8 months of losartan administration. The prevalence and complexity of ventricular arrhythmias, and the frequency of supraventricular arrhythmias were increased in hypertensive patients with LVH compared to normotensive controls and athletes, at baseline. A similar significant reduction of blood pressure (BP) was noted in both groups of patients (p < 0.001). The LVH was reduced in hypertensives with LVH (the left ventricular mass index by 12%, the interventricular septum by 8.1%, the posterior wall by 7%, all p < 0.01). However, the arrhythmias did not change in either group of patients, even if all hypertensives were considered as 1 group. In conclusion, an 8-month course with losartan was effective in lowering BP and reducing LVH. However, the increased arrhythmias, which were registered in hypertensive patients with LVH at baseline, did not change.

[Holter EKG for the hypertensive heart disease]

During chronic mechanical overload induced by hypertension, left ventricular hypertrophy predisposes to atrial and ventricular arrhythmias. Atrial arrhythmias, mainly atrial fibrillation, decrease cardiac output and increase the risk of embolism whereas ventricular arrhythmias remain the major cause of sudden death. In hypertensive patients, Holter EKG recordings frequently detect atrial or ventricular premature beats and more rarely atrial or ventricular tachycardia. In these patients, the presence of non-sustained ventricular tachycardia is considered as an independent predictor of mortality. Moreover, this non invasive method through the assessment of heart rate variability allows the study of the autonomic control of the heart, known to modulate occurrence of arrhythmias.