| 摘要 |
<p>An implantable medical device to deliver cardioverting energy to cardiac tissue in synchrony with detected ventricular depolarizations. The energy renders refractory areas of the heart associated with a reciprocating or automatic tachycardia, thus reverting these tachyarrhythmias to normal sinus rhythm without the risk of stimulating the heart during the vulnerable portion of repolarization. A QRS detector (18) detects naturally occurring cardiac electrical activity and tachy detector (20) provides an output when the heart rate is above a predetermined rate. Synch detector 24 provides an output when a ventricular depolarisation occurs during tachycardia and logic (30) then causes a cardioverting pulse to be delivered to the heart (10) by energy converter (36) and store (38). A demand pacemaker (34) supplies a pacing pulse if no cardiac depolarisation is detected within a preset escape interval.</p> |
