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Ventricular dysrhythmias in middle-aged hypertensive men treated either with a diuretic agent or a beta-blocker
Insights
Diuretic treatment in hypertensive men increases cardiac arrhythmias like ventricular premature beats (VPBs). Low serum potassium (hypokalemia) is linked to these arrhythmias, suggesting it should be avoided in older hypertensive males.
Area of Science:
- Cardiology
- Pharmacology
Background:
- Hypertension is a common condition in middle-aged males.
- Diuretics and beta-blockers are standard treatments for hypertension.
- Cardiac dysrhythmias can be a complication of antihypertensive therapy.
Purpose of the Study:
- To compare the frequency of cardiac dysrhythmias in hypertensive males treated with diuretics versus beta-blockers.
- To investigate the relationship between serum electrolytes and cardiac dysrhythmias in this population.
Main Methods:
- 24-hour ambulatory Holter monitoring was performed on all patients.
- Serum potassium and magnesium levels were measured.
- Patients were divided into two groups: diuretic treatment (n=42) and beta-blocking agent (n=41).
Main Results:
- The diuretic group showed a significantly higher mean number of ventricular premature beats (VPBs) and complex arrhythmias (19 vs. 5, p<0.01).
- Serum potassium was significantly lower in the diuretic group (p<0.001).
- An inverse correlation was found between VPBs and serum potassium (p<0.005); hypokalemia predisposes to arrhythmias.
Conclusions:
- Diuretic therapy in older hypertensive males is associated with an increased frequency of VPBs and complex arrhythmias.
- Hypokalemia is a significant risk factor for cardiac dysrhythmias in this patient group.
- Avoiding hypokalemia is recommended in older men with mild hypertension.
Abstract:
The purpose of this study was to identify the frequency of cardiac dysrhythmias in two similar groups of hypertensive middle-aged males (age 45-66). They had previously been randomized either to a diuretic treatment (n = 42), or a beta-blocking agent (n = 41). A 24-hour ambulatory Holter monitoring, and serum potassium, was obtained in all patients, serum magnesium was measured in 35 patients. The mean number of ventricular premature beats (VPBs) and the frequency of complex arrhythmias (19 vs. 5) was significantly higher in the diuretic group (p less than 0.01). The serum potassium was significantly lower (p less than 0.001) in the diuretic group, and there was a significant (p less than 0.005) inverse correlation between the number of VPBs and the serum potassium in all treated patients. The patients with complex arrhythmias were older (p less than 0.01) than the remainder of the patients. No correlation between serum magnesium and VPBs or complex arrhythmias was found. This study demonstrates increased frequency of VPBs in older hypertensive males, treated with diuretics, and that hypokalaemia predisposes to increased cardiac arrhythmias. We conclude that in older mildly hypertensive men hypokalaemia should be avoided.