Ventricular electrical activation in cardiac resynchronization as characterized by body surface potential mapping.

OBJECTIVES: To assess cardiac electrical activation by using body surface potential mapping (BSPM), in patients with congestive heart failure (CHF) and left bundle branch block (LBBB) undergoing cardiac resynchronization therapy (CRT) with biventricular pacemaker (BIV-PM) implantation. METHODS: Mean cardiac electrical activation times were analyzed in the right ventricle (RV) (mean RV activation time = mRV), anteroseptal area (mAS), and left ventricle (mLV) of 28 patients (mean age 61.2 +/- 9.5 years; NYHA class III-IV CHF; ejection fraction <40%; LBBB of mean QRS 181.2+/-19.4 ms, SAQRS -8.5 masculine+/-68.6 masculine), as shown in their BSPM isochronous maps, before and after implantation of atriobiventricular pacemaker, comparing those with values obtained from a control group of normal individuals [CG], in three situations: (1) native LBBB; (2) RV pacing; and (3) atriobiventricular pacing. RESULTS: Situation (1): mRV and mAS values were similar (41.0+/-11.8 ms x 43.6+/-13.4 ms), with delayed mLV (81.0+/-12.5 ms, p<0.01) and asynchronous with RV and AS areas; situation (2): mRV was greater than in CG (86.8+/-22.9 ms, p<0.001), with greater difference between mAS and mLV (63.4+/-20.7 ms vs. 102.7+/-20.3 ms; p<0,001); situation (3): mLV and mRV were similar (72.0+/-32.0 ms vs. 71.6+/-32.3 ms), mRV was greater than in CG and native LBBB (71.6+/-32.3 ms vs. 35.1+/-10.9 ms and 41.0+/-11.8 ms; p<0.001), and mAS was close to CG and native LBBB values (51.3+/-32.8 ms vs. 50.1+/-11.4 ms and 43.6+/-13.4 ms). CONCLUSION: The body surface potential mapping showed that RV and LV activation times which are similar, and are close to those of the AS area, suggest patterns of synchronized ventricular activation in patients with CHF and LBBB during atriobiventricular pacing.

Ativação elétrica ventricular na ressincronização cardíaca caracterizada pelo mapeamento eletrocardiográfico de superfície / Ventricular electrical activation in cardiac resynchronization as characterized by body surface potential mapping

OBJETIVOS: Avaliar a ativação elétrica cardíaca usando Mapeamento Eletrocardiográfico de Superfície (MES), em pacientes com ICC e bloqueio de ramo esquerdo [BRE] submetidos a terapia de ressincronização cardíaca (CRT) com implante de marca-passo átrio-biventricular (MP-BIV). MÉTODOS: Foram analisados os tempos médios de ativação elétrica cardíaca no ventrículo direito (tempo médio de ativação do VD [mVD]), área ântero-septal (mAS), e ventrículo esquerdo (mVE), de 28 pacientes (idade média 61,2±9,5 anos, ICC classe III-IV NYHA, fração de ejeção <40 por cento, BRE com QRS médio 181,2±19,4ms, SAQRS= -8,5°±68,6°), mostrados nos mapas de linhas isócronas do MES, antes e após implante de marca-passo átrio-biventricular, e comparados a valores obtidos em um grupo controle composto de indivíduos normais [GNL], em três situações: (1) BRE nativo, (2) estimulação do VD; e (3) estimulação átrio-biventricular. RESULTADOS: situação (1): mVD e mAS foram semelhantes (41,0±11,8ms x 43,6±13,4ms), com mVE tardio (81,0±12,5ms, p<0,01) perdendo o sincronismo com o VD e a área ântero-septal; situação (2): mVD foi maior que no GNL (86,8±22,9ms, p<0,001), com maior diferença entre mAS e mVE (63,4±20,7ms x 102,7±20,3ms; p<0,001); situação (3): mVE e mVD foram semelhantes (72,0±32,0ms x 71,6±32,3ms), mVD foi maior que no GNL e BRE nativo (71,6±32,3ms x 35,1±10,9ms e 41,0±11,8ms; p<0,001), mAS se aproximou do GNL e BRE nativo (51,3±32,8ms x 50,1±11,4ms e 43,6±13,4ms). CONCLUSÃO: Pelo mapeamento eletrocardiográfico de superfície, tempos de ativação semelhantes no VD e VE e próximos daqueles da região ântero-septal indicam padrões de ativação ventricular sincronizada em portadores de ICC e BRE durante estimulação átrio-biventricular.

OBJECTIVES: To assess cardiac electrical activation by using body surface potential mapping (BSPM), in patients with congestive heart failure (CHF) and left bundle branch block (LBBB) undergoing cardiac resynchronization therapy (CRT) with biventricular pacemaker (BIV-PM) implantation. METHODS: Mean cardiac electrical activation times were analyzed in the right ventricle (RV) (mean RV activation time = mRV), anteroseptal area (mAS), and left ventricle (mLV) of 28 patients (mean age 61.2 ± 9.5 years; NYHA class III-IV CHF; ejection fraction <40 percent; LBBB of mean QRS 181.2±19.4ms, SAQRS -8.5°±68.6°), as shown in their BSPM isochronous maps, before and after implantation of atriobiventricular pacemaker, comparing those with values obtained from a control group of normal individuals [CG], in three situations: (1) native LBBB; (2) RV pacing; and (3) atriobiventricular pacing. RESULTS: Situation (1): mRV and mAS values were similar (41.0±11.8ms x 43.6±13.4ms), with delayed mLV (81.0±12.5ms, p<0.01) and asynchronous with RV and AS areas; situation (2): mRV was greater than in CG (86.8±22.9ms, p<0.001), with greater difference between mAS and mLV (63.4±20.7ms vs. 102.7±20.3ms; p<0,001); situation (3): mLV and mRV were similar (72.0±32.0ms vs. 71.6±32.3ms), mRV was greater than in CG and native LBBB (71.6±32.3ms vs. 35.1±10.9ms and 41.0±11.8ms; p<0.001), and mAS was close to CG and native LBBB values (51.3±32.8ms vs. 50.1±11.4ms and 43.6±13.4ms). CONCLUSION: The body surface potential mapping showed that RV and LV activation times which are similar, and are close to those of the AS area, suggest patterns of synchronized ventricular activation in patients with CHF and LBBB during atriobiventricular pacing.

Body surface potential mapping investigating the ventricular activation patterns in the cardiac resynchronization of patients with left bundle-branch block and heart failure.

Body surface potential mapping assessed mean cardiac electrical activation times displayed by isochronal maps in the right ventricle (RV; right ventricle mean activation time [mRV]), anterior septal area (anterior septal area mean activation time [mAS]), and left ventricle (left ventricle mean activation time [mLV]) of 28 patients (mean, 61.07 years; congestive heart failure class III-IV; ejection fraction, < or =40%; left bundle-branch block [LBBB] QRS, 180.17 milliseconds), before and after biventricular pacemaker implantation, comparing them, using reference values from a control group of healthy individuals with normal hearts (GNL), in (1) baseline native LBBB, where mRV and mAS values were similar (40.99 vs 43.62 milliseconds), with mLV delayed (80.99 milliseconds, P < .01) and dyssynchronous with RV/anterior septal area; (2) single-site RV pacing, where mRV was greater than in GNL (86.82 milliseconds, P < .001), with greater mAS/mLV difference (63.41 vs 102.7 milliseconds; P < .001); and (3) biventricular pacing (BIV-PM), where mLV and mRV were similar (71.99 vs 71.58 milliseconds), mRV was greater than in GNL and native LBBB (71.58 vs 35.1 and 40.99 milliseconds; P < .001), and mAS approached values in GNL and native LBBB (51.28 vs 50.14 and 43.62 milliseconds). Body surface potential mapping showed that similar RV/left ventricle activation times during biventricular pacing, nearing mAS, indicate synchronized ventricular activation pattern in patients with congestive heart failure/LBBB.

Repercussions of digoxin, digitoxin and estradiol on the endometrial histomorphometry of oophorectomized mice.

The digitalics (digoxin and digitoxin) have an estrogenic action, confirmed by the presence of gynecomastia observed in men who are users of steroids, and it is also confirmed by the increase of vaginal trophism in postmenopausal female users, although little is known about the endometrium. These effects might result from the similarity of the chemical structures between the digitalics and estrogens. This study evaluated 27 female mice. Twenty-four mice were oophorectomized and in three of them the ovaries were manipulated, but they were not extirpated. Forty days after the surgery each group of three animals received a medication with a specific drug (digoxin, digitoxin or estradiol) for 2 weeks. Twenty-four hours after the last medication, all the animals were hysterectomized and the wombs were processed, cut and put on laminae. By histomorphometry, we analysed the area of the transverse sections of the endometrium, the area of the endometrial glands and the height of the uterine epithelium. The respective averages and the standard deviations were calculated. The results showed that digoxin neither presented an estrogenic action (p > 0.05) nor raised the power of the estradiol action (p > 0.05). Digitoxin promoted an estrogenic action on the glandular area (p < 0.05), and also raised the power of the estradiol action on the transverse section of the endometrium and on the glandular area (p < 0.05).

Electrocardiographic and vectorcardiographic findings of patients undergoing reductive ventriculectomy (Batista operation).

BACKGROUND: The Batista operation, or partial ventriculectomy, has been designed by the Brazilian surgeon Dr. Randas Batista as an alternative method for treating patients with idiopathic dilated cardiomyopathy. HYPOTHESIS: This study aimed to analyze electro- and vectorcardiographic data obtained from patients who underwent such surgery, and to evaluate its electrical repercussions on the heart. METHODS: Pre- and postoperative electrocardiography (ECG) and vectorcardiography (VCG) were performed 45 days apart in 15 patients undergoing reductive ventriculectomy. RESULTS: All ECGs showed sinus rhythm, with unchanged QRS duration. Left atrial enlargement (86.6%) and left ventricular hypertrophy (100%) were the most common findings. Bundle-branch blocks (BBBs) were often demonstrated on preoperative studies, predominantly (46.7%) left BBBs. Left anterior fascicular blocks were seen in four patients (26.6%), one associated with right BBB. Electrocardiographic changes suggestive of myocardial infarction (MI) were seen in four patients preoperatively; postoperatively, all had extended to or within the lateral wall. Five additional patients developed lateral MIs postoperatively, for a total of 9 patients (60%) with postoperative signs of infarction (p < 0.05). Electro- and vectorcardiography also showed significant postoperative lowering of QRS voltages (mean 40.74%) in all patients and a consequent difficulty to diagnose left ventricular hypertrophy, although the morphologic features did not change. CONCLUSIONS: These important ECG and VCG alterations are reflections of both the surgical technique and its clinical consequences.

Sildenafil effects on exercise, neurohormonal activation, and erectile dysfunction in congestive heart failure: a double-blind, placebo-controlled, randomized study followed by a prospective treatment for erectile dysfunction.

BACKGROUND: Erectile dysfunction (ED) is common in patients with congestive heart failure (CHF). ED reduces quality of life, and it may affect compliance, thereby impairing the success of CHF treatment. METHODS AND RESULTS: In the first phase (fixed-dose double-blind, randomized, placebo-controlled, two-way crossover study), we studied in 23 men with CHF the effects of 50 mg sildenafil on exercise and neurohormonal activation. Patients underwent a treadmill 6-minute cardiopulmonary walking (6'WT) test followed by a maximal cardiopulmonary exercise test (ET). In the second phase, patients received sildenafil, taken as required for ED. Sildenafil reduced the heart rate (HR) (bpm) before the 6'WT (from 75+/-15 to 71+/-14, P=0.02) and ET (from 75+/-15 to 71+/-15, P=0.02); the systolic blood pressure (mm Hg) before the 6'WT (from 116+/-18 to 108+/-18, P=0.004) and ET (from 116+/-15 to 108+/-17, P=0.001); the diastolic blood pressure before the 6'WT (from 69+/-9 to 63+/-11, P=0.01) and ET (from 70+/-8 to 65+/-10, P=0.004); and the Ve/VCO2 slope during the 6'WT (from 32+/-7 to 31+/-6, P=0.04) and ET (from 33+/-8 to 31+/-5, P=0.03). Sildenafil attenuated the HR increment during the 6'WT (P=0.003) and ET (P=0.000). Sildenafil increased the peak *O2 from 16.6+/-3.4 to 17.7+/-3.4 mL/kg per min (P=0.025) and the exercise time from 12.3+/-3.4 to 13.7+/-3.2 minutes (P=0.003). Sildenafil improved most scores of International Index of Erectile Function. CONCLUSIONS: Sildenafil was tolerated and effective for ED treatment in CHF, and improved the exercise capacity. The reduction of HR during exercise with sildenafil could theoretically decrease the myocardial oxygen consumption during sexual activity.

Exercício e insuficiência cardíaca. Estudo da relaçäo da gravidade da doença com o limiar anaeróbico e o ponto de compensaçäo respiratório / Exercise and heart failure. Relation of the severity of the disease to the anaerobic threshould and the respiratory compensation point

OBJECTIVE - To identify, the anaerobic threshold and respiratory compensation point in patients with heart failure. METHODS - The study comprised 42 Men,divided according to the functional class (FC) as follows: group I (GI) - 15 patients in FC I; group II (GII) - 15 patients in FC II; and group III (GIII) - 12 patients in FC III. Patients underwent a treadmill cardiopulmonary exercise test, where the expired gases were analyzed. RESULTS - The values for the heart rate (in bpm) at the anaerobic threshold were the following: GI, 122_27; GII, 117_17; GIII, 114_22. At the respiratory compensation point, the heart rates (in bpm) were as follows: GI, 145_33; GII, 133_14; GIII 123_22. The values for the heart rates at the respiratory compensation point in GI and GIII showed statistical difference. The values of oxygen consumption (VO2) at the anaerobic threshold were the following (in ml/kg/min): GI, 13.6_3.25; GII, 10.77_1.89; GIII, 8.7_1.44 and, at the respiratory compensation point, they were as follows: GI, 19.1_2.2; GII, 14.22_2.63; GIII, 10.27_1.85. CONCLUSION - Patients with stable functional class I, II, and III heart failure reached the anaerobic threshold and the respiratory compensation point at different levels of oxygen consumption and heart rate. The role played by these thresholds in physical activity for this group of patients needs to be better clarified

Hormônio do crescimento na otimizaçäo do tratamento da insuficiência cardíaca refratária / Growth hormone for optimization of refractory heart failure treatment

It has been reported that growth hormone may benefit selected patients with congestive heart failure. A 63-year-old man with refractory congestive heart failure waiting for heart transplantation, depending on intravenous drugs (dobutamine) and presenting with progressive worsening of the clinical status and cachexia, despite standard treatment, received growth hormone replacement (8 units per day) for optimization of congestive heart failure management. Increase in both serum growth hormone levels (from 0.3 to 0.8 mg/l) and serum IGF-1 levels (from 130 to 300ng/ml) was noted, in association with clinical status improvement, better optimization of heart failure treatment and discontinuation of dobutamine infusion. Left ventricular ejection fraction (by MUGA) increased from 13 percent to 18 percent and to 28 percent later, in association with reduction of pulmonary pressures and increase in exercise capacity (rise in peak VO2to 13.4 and to 16.2ml/kg/min later). The patient was"de-listed" for heart transplantation. Growth hormone may benefit selected patients with refractory heart failure