title: Importance of modes of electrical termination of ventricular tachycardia for the selection of implantable antitachycardia devices.
abstract: Different implantable systems for electrical treatment of ventricular arrhythmias are available. Information about mode of termination of ventricular tachycardia (VT) helps to select the most appropriate electrical treatment for drug-resistant VT. During 158 electrophysiologic studies, the mode of termination of 215 episodes of VT was analyzed in 2 groups of patients. Group 1 consisted of 54 patients with documented monomorphic VT and group 2 of 46 patients with other documented or suspected ventricular arrhythmias. Eighty-two patients had coronary heart disease, 8 had other structural heart disease and 10 had idiopathic VT. Termination of VT was attempted using extrastimuli and overdrive pacing; direct-current (DC) shocks were given in case of syncopal VT. During 33 of 96 studies (34%) in group 1, DC shock was required to interrupt VT, compared with 45 of 62 studies (73%) in group 2 (p less than 0.001). This difference was a result of less frequent induction of immediately syncopal VT in group 1 (14 of 129 VTs, vs 40 of 86 in group 2, p less than 0.001). Non-syncopal VT could reliably and safely be terminated by pacing in 61%, irrespective of the clinical arrhythmia. Pacing-induced acceleration of VT occurred in 6% (single extrastimuli) to 36% (over-drive pacing) (mean 26%) of attempts. Subsequent DC shock was required in half of these cases. Immediate collapse after induction of VT was not related to the presence of heart disease, but was related to a combination of VT cycle length (shorter than 260 ms) and left ventricular ejection fraction (less than 40%). Antiarrhythmic drugs reduced the need for DC shock.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000638:Amiodarone / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D003327:Coronary Disease / Q000150:complications; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D011342:Procainamide / Q000627:therapeutic use; D019736:Prostheses and Implants; D012189:Retrospective Studies; D013318:Stroke Volume; D013575:Syncope / Q000150:complications; D013610:Tachycardia / Q000503:physiopathology / Q000628:therapy*
chemical_list: D000889:Anti-Arrhythmia Agents; D011342:Procainamide; D000638:Amiodarone