Pulmonary Edema after Electroversion of Cardiac Dysrhythmias

Abstract

In a recent article, 1 Sutton RB Tsagaris TJ Pulmonary edema following direct current cardioversion. Chest. 1970; 57: 191 Abstract Full Text Full Text PDF PubMed Scopus (18) Google Scholar Doctors Sutton and Tsagaris reported the development of pulmonary edema following the electroversion of atrial fibrillation to sinus rhythm in a patient in severe heart failure, presumably due to cardiomyopathy, and suggest that this complication is uncommon. Since the initial report, 2 Resnekov L McDonald L Pulmonary oedema following treatment of arrhythmias by direct current shock. Lancet. 1965; 1: 506 Abstract PubMed Scopus (23) Google Scholar it has become clear that pulmonary edema following electroversion is not rare, and indeed occurred in seven patients in a consecutive series of 220 who were treated for atrial dysrhythmias or ventricular tachycardia, an incidence of more than 3 percent, whereas the incidence of all complications in that series was 14.5 percent. 3 Resnekov L McDonald L Complications in 220 patients with cardiac dysrhythmias treated by phased direct current shock, and indications for electroconversion. Brit Heart J. 1967; 29: 926 Crossref PubMed Scopus (158) Google Scholar As already emphasized, pulmonary edema after direct current shock is unlike any of the other major complications of the technique (elevation of the level of serum enzymes, hypotension, myocardial damage, embolism, skin burns, serious rhythm disturbances) in that it seems to occur only in patients actually brought into sinus rhythm. We have recorded this complication recurring when patients who reverted to atrial fibrillation were treated by phased direct current shock for a second time. Many other workers have confirmed the occurrence of pulmonary edema in sinus rhythm after DC shock. 4 Honey M Nicholls TT Towers MK Pulmonary oedema following direct current defibrillation. Lancet. 1965; 1: 765 Abstract PubMed Scopus (12) Google Scholar , 5 Paloheimo JA Pulmonary oedema after defibrillation (letter). Lancet. 1965; 2: 439 Abstract PubMed Scopus (15) Google Scholar , 6 Turner JRB Towers MK Complications of cardioversion (letter). Lancet. 1965; 2: 612 Abstract PubMed Scopus (24) Google Scholar , 7 J. Lindsay Jr Pulmonary edema following cardioversion Amer Heart J 74 1967 434 Google Scholar It is not due to a sudden increase in cardiac output with the establishment of sinus rhythm, for at rest the output of the heart is changed only slightly or not at all with the onset of sinus rhythm, 8 Resnekov L: Synchronized capacitor discharge in the management of cardiac dysrhythmias with particular reference to the haemodynamic significance of atrial systole. M.D. Thesis, University of Cape Town, 1965 Google Scholar In our series of patients, the complications occurred especially in those treated with energy level settings of 300 joules or more, apart from one patient with cardiomyopathy whose ventricular tachycardia was converted to sinus rhythm by a shock using an energy setting of 150 joules and who, nevertheless, developed severe pulmonary edema. T-wave inversion and elevation of the serum enzymes sometimes occur as well and suggest that myocardial damage might be a factor. As the complication seems to occur exclusively in those brought into sinus rhythm, a different mechanism almost certainly must also occur. Our experimental work demonstrated considerable depression of mechanical function of the left atrium following DC shock, and Logan et al 9 Logan WFWE Rowlands DJ Howitt G Holmes AM Left atrial activity following cardioversion. Lancet. 1965; 2: 471 Abstract PubMed Scopus (43) Google Scholar have shown that the same occurs in man, despite apparently normal right atrial function. Any additional obstruction to flow across the mitral valve or any left ventricular dysfunction would tend to aggravate the situation and could result in pulmonary edema occurring. 10 Bell HE Direct current shock for atrial fibrillation. Lancet. 1966; 2: 911 Google Scholar Of particular interest are the accounts of Broch and Müller 11 Broch OJ Müller O Haemodynamic studies during auricular fibrillation and after restoration of sinus rhythm. Brit Heart J. 1957; 19: 222 Crossref PubMed Scopus (11) Google Scholar who showed an elevation of the pulmonary capillary pressure which followed the quinidine conversion of atrial fibrillation to sinus rhythm, and especially that of Hollman and Nicholson 12 Hollman A Nicholson H Direct current shock for atrial fibrillation. Lancet. 1966; 2: 801 Abstract Google Scholar who reported the onset of severe pulmonary edema which followed the spontaneous reversion to sinus rhythm of a five-month episode of atrial fibrillation.