Synchronized Low Energy Transvenous Cardioversion
In this study, we present one data on the use of trans venous cardioversion with synchronized shocks of low energies via a catheter electrode.
Animal studies: After a two hour occlusion of the LAD 35 dogs underwent programmed electrical stimulation. The induced VT was terminated with transvenous cardioversion using 10 F electrode catheters (Medtronic 6880) connected to a Medtronic 2316 cardioverter. This delivered a truncated exponential wave form, approximately 6 msec in duration with. increasing energy levels from 0.0005–2.5 J.
Of the 30 sustained VT, cycle length ⋝ 200 msec, 83% were terminated reproducibly by shocks of ⋜ 1.0 and 67% ⋜ 0.5 J.
For shocks introduced within the first 80% of the QRS, RVRs were rare and acceleration or degeneration to fibrillation never occurred. For shocks introduced within the vulnerable period (ST -T) energies of 0.008 J accelerated the VT or produced ventricular fibrillation.
Human studies were performed in 13 pts with coronary artery disease (55–72 y old). In II patients on one or more occasions the transvenous cardioversion terminated VT with energies of 0.025 to 2.0 J.
Including subthreshold attempts, a total of 196 shocks was delivered. Awake unsedated patients tolerated shocks of > 0.5 J without difficulty. Shocks< 0.5 J produced moderate skeletal muscle stimulation.
In the future the ideal implantable device will be capable of transvenous cardioversion and, if that fails or if ventricular fibrillation is precipitated, it will then deliver automatically a defibrillating shock.
KeywordsCatheter Sine Lidocaine Digoxin Amiodarone
Garan H, Fallon JT, Ruskin IN: Sustained ventricular tachycardia in recent canine myocardial infarction. Circulation 1980; 62: 980.CrossRefPubMedGoogle Scholar
Harris AS: Delayed development of ventricular ectopic rhythms following experimental coronary occlusio·n. Circulation 1950; I: 1318.CrossRefGoogle Scholar
Jackman WM, Zipes DP: Low-energy synchronous cardioversion of ventricular tachycardia using a catheter electrode in a canine model of subacute myocardial infarction. Circulation 1982; 66: 187.CrossRefPubMedGoogle Scholar
Karagueuzian HS, Fenoglio JJ, Jr, Weiss MB, Wit AL: Protracted ventricular tachycardia induced by premature stimulation of the canine heart after coronary artery occlusion and reperfusion. Circ Res 1979; 44: 833.CrossRefPubMedGoogle Scholar
Kerber RE, Martins JB, Gascho JA et al: Effect of direct-current countershocks on regional myocardial contractility and perfusion. Circulation 1981; 63: 323.CrossRefPubMedGoogle Scholar
Lesigne C, Levy B, Saumont R et al: An energy-time analysis of ventricular fibrillation and defibrillation thresholds with internal electrodes. Med Bioi Eng 1976; 14: 617.CrossRefGoogle Scholar
Lown B: Electrical reversion of cardiac arrhythmias. Br Heart J 1967; 29: 469.CrossRefPubMedPubMedCentralGoogle Scholar
Michaelson EL, Spear JF, Moore EN: Initiation of sustained ventricular tachyarrhythmias in a canine model of chronic myocardial infarction: importance of the site of stimulation. Circulation 1981;63:776.CrossRefGoogle Scholar
Mirowski M, Reid PR, Mower M et al: Termination of malignant ventricular arrhythmias with an implanted automatic defibrillator in human beings. New Engl J Med 1980; 303(6): 322.CrossRefPubMedGoogle Scholar
Mirowski M, Reid PR, Watkins L et al: Clinical treatment of life-threatening ventricular tachyarrhythmias with the automatic implantable defibrillator. Am Heart J 1981; 102: 265.CrossRefPubMedGoogle Scholar
Rubin L, Hudson P, Snively S et al: Defibrillation threshold energy and epicardial electrode size (abstr.). Med Instrum 1980; 14: 58.Google Scholar
Ruskin IN, DiMarco JP, Garan H: Out-of-hospital cardiac arrest. Electrophysiologic observations and selection oflong-term antiarrhythmic therapy. New Engl J Med 1980; 303: 607.CrossRefPubMedGoogle Scholar
Schuder JC, Rahmoeller GA, Stoeckle H: Transthoracic ventricular defibrillation with triangular and trapezoidal waveforms. Circ Res 1966; 19: 689.CrossRefGoogle Scholar
Wiggers CJ, Wegria R: Ventricular fibrillation due to single, localized induction and condenser shocks applied during the vulnerable phase of ventricular systole. Am J Physiol 1940; 128: 500.Google Scholar
Yee R, Zipes DP, Gulamhusein S et al: Countershock using an intravascular catheter in an acute care setting. Am J Cardiol 1982; 50: 1124.CrossRefPubMedGoogle Scholar
Zipes DP, Jackman W, Heger JJ et al: Clinical transvenous cardioversion of recurrent lifethreatening ventricular tachyarrhythmias: low energy synchronized cardioversion of ventricular tachycardia and termination of ventricular fibrillation in patients using a catheter electrode. Am Heart J 1982; 103: 789.CrossRefPubMedGoogle Scholar
Zipes DP, Prystowsky EN, Browne K et al: Additional observations on transvenous cardioversion of recurrent ventricular tachycardia. Am Heart J 1982; 104: 163.CrossRefPubMedGoogle Scholar
Zipes DP, Prystowsky EN, Miles W, Brown J, Heger JJ: Implantable transvenous cardioverter. J Am Coli Cardiol (abstract). In press 1984.Google Scholar
© Dr. Dietrich Steinkopff Verlag, GmbH & Co. KG, Darmstadt 1983