Improved relationship between left and right ventricular electrical activation after cardiac resynchronization therapy in heart failure patients can be quantified by body surface potential mapping.

OBJECTIVES: Few studies have evaluated cardiac electrical activation dynamics after cardiac resynchronization therapy. Although this procedure reduces morbidity and mortality in heart failure patients, many approaches attempting to identify the responders have shown that 30% of patients do not attain clinical or functional improvement. This study sought to quantify and characterize the effect of resynchronization therapy on the ventricular electrical activation of patients using body surface potential mapping, a noninvasive tool. METHODS: This retrospective study included 91 resynchronization patients with a mean age of 61 years, left ventricle ejection fraction of 28%, mean QRS duration of 182 ms, and functional class III/IV (78%/22%); the patients underwent 87-lead body surface mapping with the resynchronization device on and off. Thirty-six patients were excluded. Body surface isochronal maps produced 87 maximal/mean global ventricular activation times with three regions identified. The regional activation times for right and left ventricles and their inter-regional right-to-left ventricle gradients were calculated from these results and analyzed. The Mann-Whitney U-test and Kruskall-Wallis test were used for comparisons, with the level of significance set at p≤0.05. RESULTS: During intrinsic rhythms, regional ventricular activation times were significantly different (54.5 ms vs. 95.9 ms in the right and left ventricle regions, respectively). Regarding cardiac resynchronization, the maximal global value was significantly reduced (138 ms to 131 ms), and a downward variation of 19.4% in regional-left and an upward variation of 44.8% in regional-right ventricular activation times resulted in a significantly reduced inter-regional gradient (43.8 ms to 17 ms). CONCLUSIONS: Body surface potential mapping in resynchronization patients yielded electrical ventricular activation times for two cardiac regions with significantly decreased global and regional-left values but significantly increased regional-right values, thus showing an attenuated inter-regional gradient after the cardiac resynchronization therapy.

Improved relationship between left and right ventricular electrical activation after cardiac resynchronization therapy in heart failure patients can be quantified by body surface potential mapping

OBJECTIVES: Few studies have evaluated cardiac electrical activation dynamics after cardiac resynchronization therapy. Although this procedure reduces morbidity and mortality in heart failure patients, many approaches attempting to identify the responders have shown that 30% of patients do not attain clinical or functional improvement. This study sought to quantify and characterize the effect of resynchronization therapy on the ventricular electrical activation of patients using body surface potential mapping, a noninvasive tool. METHODS: This retrospective study included 91 resynchronization patients with a mean age of 61 years, left ventricle ejection fraction of 28%, mean QRS duration of 182 ms, and functional class III/IV (78%/22%); the patients underwent 87-lead body surface mapping with the resynchronization device on and off. Thirty-six patients were excluded. Body surface isochronal maps produced 87 maximal/mean global ventricular activation times with three regions identified. The regional activation times for right and left ventricles and their inter-regional right-to-left ventricle gradients were calculated from these results and analyzed. The Mann-Whitney U-test and Kruskall-Wallis test were used for comparisons, with the level of significance set at p≤0.05. RESULTS: During intrinsic rhythms, regional ventricular activation times were significantly different (54.5 ms vs. 95.9 ms in the right and left ventricle regions, respectively). Regarding cardiac resynchronization, the maximal global value was significantly reduced (138 ms to 131 ms), and a downward variation of 19.4% in regional-left and an upward variation of 44.8% in regional-right ventricular activation times resulted in a significantly reduced inter-regional gradient (43.8 ms to 17 ms). CONCLUSIONS: Body surface potential mapping in resynchronization patients yielded electrical ventricular ...

Global and regional ventricular repolarization study by body surface potential mapping in patients with left bundle-branch block and heart failure undergoing cardiac resynchronization therapy.

BACKGROUND: The controversial effects promoted by cardiac resynchronization therapy (CRT) on the ventricular repolarization (VR) have motivated VR evaluation by body surface potential mapping (BSPM) in CRT patients. METHODS: Fifty-two CRT patients, mean age 58.8 ± 12.3 years, 31 male, LVEF 27.5 ± 9.2, NYHA III-IV heart failure with QRS181.5 ± 14.2 ms, underwent 87-lead BSPM in sinus rhythm (BASELINE) and biventricular pacing (BIV). Measurements of mean and corrected QT intervals and dispersion, mean and corrected T peak end intervals and their dispersion, and JT intervals characterized global and regional (RV, Intermediate, and LV regions) ventricular repolarization response. RESULTS: Global QTm (P < 0.001) and QTc(m) (P < 0.05) were decreased in BIV; QTm was similar across regions in both modes (P = ns); QTc(m) values were lower in RV/LV than in Intermediate region in BASELINE and BIV (P < 0.001); only RV/Septum showed a significant difference (P < 0.01) in the BIV mode. QTD values both of BASELINE (P < 0.01) and BIV (P < 0.001) were greater in the Intermediate than in the LV region. CRT effect significantly reduced global/regional QTm and QTc(m) values. QTD was globally decreased in RV/LV (Intermediate: P = ns). BIV mode significantly reduced global T peak end mean and corrected intervals and their dispersion. JT values were not significant. CONCLUSIONS: Ventricular repolarization parameters QTm, QTc(m), and QTD global/regional values, as assessed by BSPM, were reduced in patients under CRT with severe HF and LBBB. Greater recovery impairment in the Intermediate region was detected by the smaller variation of its dispersion.

Prevenção secundária da morte súbita: importância do marcapasso definitivo prévio ao implante de cardioversor-desfibrilador implantável (CDI) na sobrevida de pacientes com miocardiopatia chagásica / The relevance of previous permanent pacemaker implant in the survival actuarial curve of chagaapóstrofos ICD patients

Objetivo: Avaliar a importância clínica da presença de marcapasso definitivo (MPD) previamente ao implante de CDI de nossa instituição, foram selecionados 275 submetidos a implante de CDI para prevenção secundária de morte súbita cardíaca (MSC), agrupados de acordo com a cardiomiopatia de base e a presença de MPD prévio ao implante de CDI. As variáveis analisadas foram: sexo, idade, CF-NYHAA, medicações, ritmo cardíaco, FEVE e TVNS. Para análise estatística, utilizou-se o método de Kaplan Meier e o teste de log-rank. Resultados: A amostra reduzida de pacientes com consistentes...

A ressincronização ventricular altera o prognóstico de pacientes com insuficiência cardíaca e arritmias ventriculares complexas? / Does cardiac resynchronization modify the prognosis of patients with heart failure and complex ventricular arrhythmias?

A terapêutica atual da insuficiência cardíaca baseou-se na compreensão da fisiopatologia dos mecanismos envolvidos na progressão da doença. O bloqueio de ramo esquerdo proporciona modificações da seqüência de ativação ventricular, com piora da função sistólica, do débito cardíaco e da função diastólica, sendo o bloqueio de ramo esquerdo fator de risco independente para maior morbidade e mortalidade. O estudo MIRACLE demonstrou melhora progressiva de parâmetros funcionais (IC-NYHA, tempo de caminhada de 6 minutos e qualidade de vida), além de redução do ventrículo esquerdo de pacientes com insuficiência cardíaca avançada submetidos a ressincronização cardíaca, definindo, assim, o papel da estimulação cardíaca em longo prazo na terapêutica da insuficiência cardíaca, e sendo considerada nova terapêutica para insuficiência cardíaca (American Heart Association ù classe IIA), em portadores de insuficiência cardíaca III e IV, refratários à terapêutica medicamentosa, com QRS >130 ms, diâmetro diastólico > 55 mm e fração de ejeção < 35 por cento.Bradley, em meta-análise (CONTAK CD, InSync ICD, MIRACLE, MUSTIC) com 1.634 pacientes, registrou redução da mortalidade de 3,5 por cento no grupo controle para 1,7 por cento, com redução relativa de 51 por cento na mortalidade por insuficiência cardíaca, e redução de 29 por cento nas hospitalizações. Em relação à mortalidade global, ocorreu redução de 23 por cento no risco relativo pela ressincronização. O estudo COMPANION demonstrou redução da mortalidade global combinada e hospitalizações de 20 por cento no grupo de ressincronização com desfibrilador-cardioversor implantável ou isolada, em relação à terapêutica clínica, com taxa de mortalidade de 19 por cento no grupo controle, 15 por cento no grupo com ressincronizador apenas e 11 por cento com ressincronizador associado a desfibrilador-cardioversor implantável. Estudos futuros deverão mensurar precisamente os efeitos da ressincronização na mortalidade total, definir o impacto econômico dessa modalidade terapêutica, e selecionar criteriosamente pacientes mais responsivos ao procedimento.

Cardiac damage from chronic use of chloroquine: a case report and review of the literature.

Chloroquine has been widely used in rheumatological treatment, but potential severe side effects require careful follow-up. Cardiac damage is not a common consequence, but its clinical relevance has not yet been described. We report the case of a 58-year-old woman with rheumatoid arthritis, in whom chronic chloroquine use resulted in major irreversible cardiac damage. She presented with syncopal episodes due to complete atrioventricular block confirmed by electrophysiological study whose changes were concluded to be irreversible and a permanent pacemaker was indicated. Endomyocardial biopsy was also performed to search for histopathological and ultrastructural cardiac damage. We also reviewed the 22 cases of chloroquine-induced cardiopathy described to date as well as its pathophysiology.

Cardiac damage from chronic use of chloroquine: a case report and review of the literature

Chloroquine has been widely used in rheumatological treatment, but potential severe side effects require careful follow-up. Cardiac damage is not a common consequence, but its clinical relevance has not yet been described. We report the case of a 58-year-old woman with rheumatoid arthritis, in whom chronic chloroquine use resulted in major irreversible cardiac damage. She presented with syncopal episodes due to complete atrioventricular block confirmed by electrophysiological study whose changes were concluded to be irreversible and a permanent pacemaker was indicated. Endomyocardial biopsy was also performed to search for histopathological and ultrastructural cardiac damage. We also reviewed the 22 cases of chloroquine-induced cardiopathy described to date as well as its pathophysiology

Biventricular pacing improves clinical behavior and reduces prevalence of ventricular arrhythmia in patients with heart failure.

PURPOSE: To analyze the influence of biventricular pacing (BP) on clinical behavior, ventricular arrhythmia (VA) prevalence, and left ventricular ejection fraction (LV EF) by gated ventriculography. METHODS: Twenty-four patients with left bundle branch block (LBBB) and NYHA class III and IV underwent pacemaker implantation and were randomized either to the conventional or BP group, all receiving BP after 6 months. RESULTS: Sixteen patients were in NYHA class IV (66.6%) and 8 were in class III (33.4%). After 1-year follow-up, 14 patients were in class II (70%) and 5 were in class III (25%). Two sudden cardiac deaths occurred. A significant reduction in QRS length was found with BP (p=0.006). A significant statistical increase, from a mean of 19.13 +/- 5.19% (at baseline) to 25.33 +/- 5.90% (with BP) was observed in LVEF Premature ventricular contraction prevalence decreased from a mean of 10,670.00 +/- 12,595.39 SD or to a mean of 3,007.00 +/- 3,216.63 SD PVC/24 h with BP (p<0.05). Regarding the hospital admission rate over 1 year, we observed a significant reduction from 60. To 16 admissions with BP (p<0.05). CONCLUSION: Patients with LBBB and severe heart failure experienced, with BP, a significant NYHA class and LVEF improvement. A reduction in the hospital admission rate and VA prevalence also occurred.

Biventricular pacing improves clinical behavior and reduces prevalence of ventricular arrhythmia in patients with heart failure

PURPOSE: To analyze the influence of biventricular pacing (BP) on clinical behavior, ventricular arrhythmia (VA) prevalence, and left ventricular ejection fraction (LV EF) by gated ventriculography. METHODS: Twenty-four patients with left bundle branch block (LBBB) and NYHA class III and IV underwent pacemaker implantation and were randomized either to the conventional or BP group, all receiving BP after 6 months. RESULTS: Sixteen patients were in NYHA class IV (66.6 per cent) and 8 were in class III (33.4 per cent). After 1-year follow-up, 14 patients were in class II (70 per cent) and 5 were in class III (25 per cent). Two sudden cardiac deaths occurred. A significant reduction in QRS length was found with BP (p=0.006). A significant statistical increase, from a mean of 19.13 ñ 5.19 per cent (at baseline) to 25.33 ñ 5.90 per cent (with BP) was observed in LVEF Premature ventricular contraction prevalence decreased from a mean of 10,670.00 ñ 12,595.39 SD or to a mean of 3,007.00 ñ 3,216.63 SD PVC/24 h with BP (p<0.05). Regarding the hospital admission rate over 1 year, we observed a significant reduction from 60. To 16 admissions with BP (p<0.05). CONCLUSION: Patients with LBBB and severe heart failure experienced, with BP, a significant NYHA class and LVEF improvement. A reduction in the hospital admission rate and VA prevalence also occurred.

Marcapasso atrioventricular. Incidência e causas de reprogramações em seguimento a longo prazo / Atrioventricular pacemaker. Incidence and causes of reprogramming in long-term follow-up

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 percent) patients underwent reprogramming of the stimulation mode as follows: 63 (9.5 percent) changed to VVI,(R/C); 10 (1.5 percent) changed to DVI,C; 6 (0.9 percent) changed to VDD,C; and 3 (0.5 percent) changed to DOO. The causes for the reprogramming were as follows: arrhythmia conducted by the pacemaker in 39 (37.6 percent) patients; loss of atrial sensitivity or capture, or both, in 39 (38.6 percent) patients; and microfracture of atrial electrode in 5 (4.9 percent) patients. The stimulation mode reprogramming free probability after 15 years was 58 percent. 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

Angioplastia coronariana transluminal percutânea após transplante cardíaco ortotópico / Percutaneous Transluminal Coronary Angioplasty After Orthotopic Cardiac Transplantation

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 per cent to 39per cent (normal value > or = 55 per cent) 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 per cent. 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 per cent to 45 per cent. 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