Cardiac Resynchronization and Implantable Cardioverter Defibrillator Therapy: Preliminary Results from the InSync Implantable Cardioverter Defibrillator Italian Registry

Abstract

The aim of this study was to evaluate ventricular arrhythmias occurring in recipients of the InSync ICD for the primary and secondary prevention of sudden death. The InSync ICD was implanted in 142 patients (128 men; mean age 65 +/- 10 years) with heart failure (mean NYHA functional Class 3.0 +/- 0.7) and wide QRS (mean 159 +/- 33 ms). The underlying etiology was ischemic in 55%, idiopathic in 33%, and valvular or hypertensive cardiomyopathy in 12% of patients. The numbers of arrhythmic episodes/100 patient-months was computed with their 95% CI, assuming a Poisson distribution. Implants were performed in 48 (34%) patients who did not have an ACC/AHA guidelines Class I indication for ICD therapy. A total of 104 patients were compliant for follow-up visits. During a 9-month median (range 0.1-24) follow-up of 104 compliant patients, 19 experienced a total of 94 ventricular arrhythmias, all successfully interrupted or self-terminated, with a median number of two separate episodes, corresponding to a rate of 10 episodes/100 person-month (95% CI 8-12). A rate of 12 episodes/100 person-months (95% CI 10-15) was measured in the subgroup of patients with ACC/AHA class I indications, versus two episodes/100 person-months (95% CI 1-5) in the remainder of the population. Among 12 deaths, 9 were due to heart failure, 1 to a non-cardiovascular cause, and 2 to unknown causes. The implantation of ICD in heart failure patients has been prominently extended to primary prevention. Patients without standard ICD indications experienced life-threatening arrhythmic events. The impact of ICD combined with cardiac resynchronization therapy on arrhythmic profile, mortality, and costs in this subgroup of patients need to be more precisely studied, with a particular focus on the various types of underlying heart disease.

A Comparison of ICD Implantations in the United States Versus Italy

“…Due to these expanded indications, the rates of ICD implantation have steadily increased in the USA and in Europe 12,13 . Several worldwide surveys and registries have examined pacing and ICD utilizations 14–16 . There is, however, paucity of data comparing ICD utilization rates in the USA versus Europe, especially in the era of primary prevention.…”

Comparison of temporary bifocal right ventricular pacing and biventricular pacing for heart failure: evaluation by tissue Doppler imaging

“…The third patient in NYHA II had conventional indications for both permanent pacing and an implantable cardioverter defibrillator. Several randomised controlled trials have included patients in NYHA II22 23 and therefore these three patients, with existing or anticipated ECG and echocardiographic evidence of dyssynchrony, were considered candidates for a biventricular device.…”

Clustering of Ventricular Tachyarrhythmias in Heart Failure Patients Implanted with a Biventricular Cardioverter Defibrillator

“…All patients were implanted with a biventricular ICD (Model InSync ICD or InSync Marquis or InSync III Marquis, Medtronic, Inc., MN, USA). These devices are dual‐chamber ICDs with biventricular pacing capabilities; they detect ventricular tachyarrhythmias according to three zones and can deliver up to six therapies, including antitachycardia pacing, and low‐ and high‐energy shocks 11,12 …”