Diuretics, potassium and arrhythmias in hypertensive coronary disease.
It has been proposed that modest changes in plasma potassium can alter the tendency towards cardiac arrhythmias. If this were so, patients with coronary artery disease might be especially susceptible. Thus, myocardial electrical excitability was measured in patients with mild essential hypertension and known coronary artery disease after 8 weeks of treatment with a potassium-conserving diuretic (amiloride) and a similar period on a potassium-losing diuretic (chlorthalidone) in a randomised study. Plasma potassium concentrations were on average 1 mmol/L lower during the chlorthalidone phase compared to amiloride therapy. Blood pressure and volume states as assessed by bodyweight, plasma renin and noradrenaline (norepinephrine) concentrations were similar on the 2 regimens. Compared to amiloride treatment, the chlorthalidone phase was associated with an increased frequency of ventricular ectopic beats (24-hour Holter monitoring) and a higher Lown grading, increased upslope and duration of the monophasic action potential, prolonged ventricular effective refractory period, and increased electrical instability during programmed ventricular stimulation. The above results indicate that because potassium-losing diuretic therapy can increase myocardial electrical excitability in patients with ischaemic heart disease, even minor falls in plasma potassium concentrations are probably best avoided in such patients.[1]References
- Diuretics, potassium and arrhythmias in hypertensive coronary disease. Ikram, H., Espiner, E.A., Nicholls, M.G. Drugs (1986) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg
