Follow-up of asystolic episodes in patients with cardioinhibitory, neurally mediated syncope and VVI pacemaker.
The occurrence rate of spontaneous asystolic episodes during long-term follow-up in patients with abnormal asystolic responses induced by means of vasovagal maneuvers was evaluated. The heart rate of 23 patients (mean age 64 +/- 12 years; 6 women and 17 men) affected by neurally mediated syncope (mean 4.3 +/- 4.9 episodes) was continuously monitored by a specially designed implanted pacemaker able to detect and store in its memory all asystolic episodes lasting 3 to 6 or > 6 seconds. Asystolic, neurally mediated syncope was diagnosed when a reflex asystole of > 3 seconds was induced during carotid sinus massage (n = 22), eyeball compression test (n = 3) or head-up tilt test (n = 2). During a total of 357 months (mean 15 +/- 7) of monitoring, asystolic episodes occurred in 17 patients (74%): 1,765 episodes of 3- to 6-second (median 3) duration occurred in 14 patients, and 47 episodes of > 6-second (median 2) duration occurred in 11. The actuarial estimates of occurrence of asystolic episodes of > 3 and > 6 seconds were 82 and 53%, respectively, after 2 years of follow-up. Only 12 episodes of 3 to 6 seconds (0.7%), and 20 episodes of > 6 seconds (43%) resulted in presyncopal or syncopal symptoms. Thus, an asystolic response to vasovagal maneuvers predicts the occurrence of spontaneous asystolic episodes during follow-up. With few exceptions, spontaneous episodes are asymptomatic and their incidence is low.
Menozzi
C
C
Laboratory of Electrophysiology and Pacing, Ospedale S. Maria Nuova, Reggio Emilia, Italy.
Brignole
M
M
Lolli
G
G
Bottoni
N
N
Oddone
D
D
Gianfranchi
L
L
Gaggioli
G
G
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015716:Electrocardiography, Ambulatory; D005260:Female; D005500:Follow-Up Studies; D006323:Heart Arrest / Q000209:etiology / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D015993:Life Tables; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013575:Syncope / Q000150:complications / Q000503:physiopathology* / Q000628:therapy; D014630:Vagus Nerve / Q000503:physiopathology*