44 prescribing for the Elderly THE MEDICAL JOURNAL OF AUSTRALIA Vol 162 2 January 1995 Congestive cardiac failure and arrhythmias Paddy A Phillips, Louise M Burrell, Andrew M Tonkin and Colin I Johnston C ongestive cardiac failure is one of the commonest medical diagnoses among patients in Australian public hospitals.' In the United States- hospital admissions for congestive heart failure have been steadily increasing, mostly in people 65 years of age or older." Despite massive use of hospital resources, the age-adjusted death rate for heart failure in the United States has changed little over the last 40 years/,3despite a worldwide fall in mor- tality from ischaemic heart disease and hypertension. In the Framingham study, ischaemic heart disease, hypertension and valvular heart disease were the most important causes of congestive cardiac failure, accounting for 54%, 24% and 16% of cases, respectively. 3 With the ageing of Western populations it may be pre- dicted that the incidence of heart failure will continue to rise. However, reports of recent trials of new therapies give hope that the morbidity and mortality may be reduced . Prognosis of congestive cardiac failure The two most important and commonest causes of death in patients with congestive heart failure are arrhythmias (sudden cardiac death) and progressive pump failure. The most important of the former are malignant ventricular arrhythmias, but bradyarrhythmias and supraventricular arrhythmias are also important . In particular, atrial fibril- lation is associated with increased mortality," In the Framingham study the one-year age-adjusted mor- tality in all patients with heart failure was 43 % for men and 36% for women, with the cumulative mortality increasing to 75 % for men and 62% for women at five years. " The prog- nosis is worse with increasing severity, such that yearly mor- tality rates increase from 12%-15 % for mild heart failure (New York Heart Association [NYHA] Class I-II) to 60% for severe heart failure (NYHA Class IV) (Box 1) .5,6 Although the mortality rate is lower in mild heart failure, the proportion of deaths due to sudden death and arrhythmias is higher (50%-60%) . In more severe heart failure, more Series Editor: Professor Nicholas Christ ophidis, PhD, FRACP. Department of Medicine, University of Melbourne, Austin Hospital, Melbourne, VIC. Paddy A Phill ips, DPhil, FRACP, Senior Lecturer in Medicine. Louise M Burrell, MRCP, MD, Senior Research Fellow. Andrew M Tonkin, FRACP, MD, Director of Cardiology. Co lin I Johnston, FRACP, Professor of Medicine. No reprints will be available. Correspondence: Dr P A Phillips, Department of Medicine, University of Melbourne, Austin Hospital, Heidelberg, VIC 3084. deaths are caused by pump failure, with arrhythmias accounting for only about 20%-30% of deaths." Drug therapy The most important principle in treating congestive cardiac failure is to address the reversible causes (such as myocar- dial ischaemia, hypertension, valvular heart disease and thy- rotoxicosis) . Nevertheless, drug therapy is increasingly beneficial in improving function and reducing mortality. 1: New York Heart Association (NYHA) classification of functional disability Class I: Cardiac disease but ordinary activity causes no symptoms Class II: Slight limitation, with ordinary activity causing symptoms Class III: Marked limitation, with symptoms on less than ordinary activity Class IV: Unable to carr yon any activity without symp- toms and may have symptoms at rest Vasodilators Treatment with vasodilators and, in particular, angiotensin- converting enzyme (ACE) inhibitors, is of major importance for all grades of left ventricular dysfunction.r-" whether asymptomatic or severe. The benefits include reduced mor- bidity, reduced admissions to hospital, reduced progression of heart failure and increased survival. 7-15 There are fewer deaths from progressive pump failure or myocardial infarc- tion rather than any appreciable reduction in sudden deaths. Oral nitrates (in combination with hydralazine) also reduce morbidity and mortality in severe congestive cardiac fail- ure ."-'? However, a comparative study showed that ACE in- hibition was more effective. Nitrates may be a suitable alternative to ACE inhibitors if patients cannot tolerate the latter, or even as an adjunct to them in certain patients such as those with myocardial ischaemia. A recently described vasodilator, flosequinan, which in- itially showed haemodynamic and therapeutic benefit, was found to cause excess mortality in heart failure, perhaps related to phosphodiesterase inhibition and the production of arrhythmias. 16