RESUMO
OBJECTIVE: To assess the incidence of problems requiring reprogramming of atrioventricular pacemakers in a long-term follow-up, and also the causes for this procedure. METHODS: During the period from May '98 to December '99, 657 patients were retrospectively studied, An actuarial curve for the event reprogramming of the stimulation mode was drawn. RESULTS: The follow-up period ranged from 12 to 178 months (mean = 81 months). Eighty-two (12.4%) patients underwent reprogramming of the stimulation mode as follows: 63 (9.5%) changed to VVI,(R/C); 10 (1.5%) changed to DVI,C; 6 (0.9%) changed to VDD,C; and 3 (0.5%) changed to DOO. The causes for the reprogramming were as follows: arrhythmia conducted by the pacemaker in 39 (37.6%) patients; loss of atrial sensitivity or capture, or both, in 39 (38.6%) patients; and microfracture of atrial electrode in 5 (4.9%) patients. The stimulation mode reprogramming free probability after 15 years was 58%. CONCLUSION: In a long-term follow-up, the atrioventricular pacemaker provided a low incidence of complications, a high probability of permanence in the DDD,C mode, and the most common cause of reprogramming was arrhythmia conducted by the pacemaker.
Assuntos
Estimulação Cardíaca Artificial , Marca-Passo Artificial , Análise Atuarial , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estimulação Cardíaca Artificial/efeitos adversos , Criança , Falha de Equipamento/estatística & dados numéricos , Feminino , Seguimentos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Marca-Passo Artificial/efeitos adversos , Estudos RetrospectivosRESUMO
The purpose of a sensor-driven pacing system is to physiologically correct chronotropic incompetence (CI). The aim of this study was to evaluate the changes in heart rate provided by a sympathetically driven pacemaker (PM) compared with normal sinus function (NSF). Nine men and six women (age 37-80 years) with AV block and a PM controlled by a closed-loop system were studied. Group I included eight patients with CI, and group II included seven patients with NSF. All patients underwent Valsalva maneuver and tilt table testing with measurements of plasma catecholamines and renin activity. Pacing was initially programmed in the DDDC mode at a lower rate (60 ppm) and upper rate limit (0.85 x [220 - age]), then in DDDR in group I and VVIR in group II. The second phase of the study consisted of nitroglycerin and phenylephrine infusions, and the third phase of physiological provocative maneuvers. The second and third phases were performed in three patients from each group with sensor activity On and Off. In group I, heart rate changed during tilt only in the DDDR mode. In group II, heart rate changes were comparable in both modes. Catecholamine levels in group I were higher during DDDC than during DDDR pacing (P < 0.05). In group I, heart rate did not change during phases II and IV of the Valsalva maneuver in the DDDC mode, but behaved nearly physiologically after sensor activation. A late and a paradoxical response to nitroglycerin was observed in groups I and II and to phenylephrine in group I. During physiological maneuvers, significantly greater variations in heart rate were observed during DDDR than during DDDC pacing. Sympathetic SDP provides physiological modulations of the heart rate were provided by a sympathetically driven pacing system in patients with AV block and CI.
Assuntos
Sistema Nervoso Autônomo/fisiopatologia , Estimulação Cardíaca Artificial/métodos , Bloqueio Cardíaco/fisiopatologia , Marca-Passo Artificial , Adulto , Idoso , Idoso de 80 Anos ou mais , Pressão Sanguínea/efeitos dos fármacos , Epinefrina/sangue , Feminino , Bloqueio Cardíaco/sangue , Bloqueio Cardíaco/terapia , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Nitroglicerina/farmacologia , Norepinefrina/sangue , Fenilefrina/farmacologia , Estudos Prospectivos , Renina/sangue , Teste da Mesa Inclinada , Manobra de ValsalvaRESUMO
Entidade clínica descrita há séculos, o bloqueio atrioventricular é determinado por uma variedade de condiçöes e processos patológicos, podendo ser de localização nodal atrioventricular ou no sistema de His-Purkinje. Pode ser assintomático ou relacionar-se a quadros de baixo fluxo cerebral e/ou insuficiência cardíaca congestiva. Em geral, o prognóstico se define pelo sítio do bloqueio no sistema de condução e pela doença que o originou. A estimulação cardíaca artificial influiu sobremaneira no tratamento dos bloqueios atrioventriculares com a melhora dos sintomas, permitindo a reintegração de seus portadores na sociedade.
Assuntos
Humanos , Bloqueio Cardíaco/etiologia , Bloqueio Cardíaco/história , Síncope , Estimulação Cardíaca Artificial , Marca-Passo Artificial , Sinais e SintomasRESUMO
We report the case of 22 year-old male who developed coronary artery disease two years after orthotopic cardiac transplantation, manifested as congestive heart failure NYHA functional class III. The left ventricular radioisotopic evaluation at rest revealed worsening of left ventricular ejection fraction from 50% to 39% (normal value > or = 55%) and septal hypokinesia. The hemodynamic and coronariographic study showed two subocclusive lesions at the mid portion and distal portion of the left descending coronary artery and the patient underwent PTCA of both lesions, successfully reducing them to 30%. A new radionuclide and echocardiographic evaluation of left ventricular function at rest, showed marked improvement of global function no regional abnormalities, increasing the ejection fraction from 39% to 45%. The patient showed improvement of NYHA functional class, passing to functional class II and was discharged home. We conclude that PTCA could be performed in a successful manner in this patient.