Haemodynamic studies before and after electrical conversion of atrial fibrillation and flutter to sinus rhythm.

The clinical use of direct current shock in the management of cardiac arrhythmias (Lown, Amarasingham, and Neuman, 1962) has been amply confirmed by many other workers (O'Brien, Resnekov, and McDonald, 1964; Oram et al., 1964; Morris et al., 1964b). The length of time that sinus rhythm persists after the electrical conversion of chronic arrhythmias is often disappointingly short, even when quinidine is prescribed (Resnekov, 1965), and complications following direct current shock are by no means infrequent (McDonald and Resnekov, 1964; Resnekov and McDonald, 1964, 1965). It seemed important therefore to determine what hwemodynamic benefit might be expected following the electrical conversion of atrial fibrillation and flutter to sinus rhythm.