Randomized Study Comparing Radiofrequency Ablation with the PVAC Gold System vs. Antiarrhythmic Drugs in Elderly Patients with Symptomatic Atrial Fibrillation. / Estudo Randomizado Comparando a Ablação por Cateter com o PVAC Gold vs. Tratamento com Fármacos Antiarrítmicos em Pacientes Idosos com Fibrilação Atrial Sintomática.

BACKGROUND: There are no randomized studies comparing the maintenance of sinus rhythm after catheter ablation (CA) concerning treatment with antiarrhythmic drugs (AA) in elderly patients with paroxysmal atrial fibrillation (AF). OBJECTIVES: To compare the clinical results of pulmonary vein (PV) isolation with the second-generation PVAC Gold catheter against AA treatment in elderly people with recurrent symptomatic paroxysmal AF, refractory to at least one AA, and without structural heart disease. METHODS: Sixty patients with paroxysmal AF ≥ 65 years old were randomized to two forms of treatment: group 1: CA and group 2: AA drugs. The primary outcome was the AF recurrence-free rate after at least one year of follow-up. Secondary outcomes were: progression to persistent forms of AF, impact on quality of life (QOLF), and complications. The significance level adopted in the statistical analysis was 5% (p<0.05). RESULTS: The AF recurrence-free rate was 80% (10% with amiodarone) in the CA group, after 1.3 procedures per patient and 65% in the AA group (60% with amiodarone), (p = 0.119) in an average follow-up of 719 days (Q1: 566; Q3: 730). The persistent AF free rate was 83.4% in the AC group and 67.7% in the AA group (p = 0.073) Both strategies showed an improvement in the AFQoL score during follow-up (p < 0.001), with no difference between the groups. Although without clinical repercussions or impact on the intellectual assessment test, 25% of patients in the CA group showed signs of cerebral embolization on brain MRI. CONCLUSIONS: Both strategies for maintaining sinus rhythm promoted an improvement in the quality of life of elderly patients with symptomatic AF, with no statistical difference in the clinical outcomes. Additional studies using technologies with a better safety profile are needed to evaluate the benefits of CA in elderly patients with AF.

FUNDAMENTO: Não existem estudos randomizados comparando a manutenção do ritmo sinusal após ablação por cateter (AC) em relação ao tratamento com fármacos antiarrítmicos (AA) em pacientes idosos portadores fibrilação atrial (FA) paroxística. OBJETIVOS: Comparar os resultados clínicos do isolamento das veias pulmonares (VPs) com o cateter PVAC Gold de segunda geração com o uso de AA em idosos com FA paroxística sintomática, recorrente, apesar do uso de fármacos AA. MÉTODOS: Sessenta pacientes com FA paroxística ≥ 65 anos e sem cardiopatias estruturais foram randomizados para duas formas de tratamento: grupo 1: AC e grupo 2: AA. O desfecho primário foi a taxa livre de recorrência de FA após pelo menos um ano de seguimento. Os desfechos secundários foram: progressão para formas persistentes de FA, impacto na qualidade de vida (QVFA) e complicações. O nível de significância adotado na análise estatística foi de 5% (p<0,05). RESULTADOS: A taxa livre de recorrência de FA foi de 80% (10% com amiodarona) no grupo AC, após 1,3 procedimentos por paciente e de 65% no grupo AA (60% com amiodarona), (p = 0,119) num seguimento médio de 719 dias (Q1: 566; Q3: 730). A taxa livre de FA persistente foi de 83,4% no grupo AC e de 67,7% no grupo AA (p = 0,073). Ambas as estratégias apresentaram melhora no escore de QVFA durante o seguimento (p < 0,001), sem diferença entre os grupos. Embora sem repercussão clínica ou impacto no teste de avaliação intelectual, 25% dos pacientes do grupo PVAC apresentou sinais de embolização cerebral na RNM cerebral. CONCLUSÕES: Ambas as estratégias para manutenção do ritmo sinusal promoveram melhora na qualidade de vida de pacientes idosos com FA sintomática, sem diferença estatística nos desfechos clínicos preconizados. Estudos adicionais usando tecnologias com melhor perfil de segurança são necessários para avaliar os benefícios da AC em pacientes idosos com FA.

Characterization of the electrocardiographic pattern of individuals with cerebral palsy.

BACKGROUND: Dentists of Lar São Francisco observed during dental treatment that children with cerebral palsy (CP) had increased heart rate (HR) and lower production of saliva. Despite the high prevalence of CP found in the literature (2.08-3.6/1000 individuals), little is known about the electrocardiographic (ECG) characteristics, especially HR, of individuals with CP. OBJECTIVE: This study aimed to investigate the hypothesis that individuals with CP have a higher HR and to define other ECG characteristics of this population. METHODS: Ninety children with CP underwent clinical examination and 12-lead rest ECG. Electrocardiographic data on rhythm, HR, PR interval, QRS duration, P/QRS/T axis, and QT, QTc and T(peak-end) intervals (minimum, mean, maximum, and dispersion) were measured and analyzed then compared with data from a control group with 35 normal children. Fisher and Mann-Whitney U tests were used, respectively, to compare categorical and continuous data. RESULTS: Groups cerebral palsy and control did not significantly differ in age (9 ± 3 × 9 ± 4 years) and male gender (65% × 49%). Children with CP had a higher HR (104.0 ± 20.6 × 84.2 ± 13.3 beats per minute; P < .0001), shorter PR interval (128.8 ± 15.0 × 138.1 ± 15.1 milliseconds; P = .0018), shorter QRS duration (77.4 ± 8.6 × 82.0 ± 8.7 milliseconds; P = .0180), QRS axis (46.0° ± 26.3° × 59.7° ± 24.8°; P = .0024) and T-wave axis (34.3° ± 28.9° × 42.9° ± 17.1°; P = .034) more horizontally positioned, and greater mean QTc (418.1 ± 18.4 × 408.5 ± 19.4 milliseconds; P = .0110). All the electrocardiogram variables were within the reference range for the age group including those with significant differences. CONCLUSION: Children with CP showed increased HR and other abnormal ECG findings in the setting of this investigation. Further studies are needed to explain our findings and to correlate the increased HR with situations such as dehydration, stress, and autonomic nervous disorders.

Biventricular imaging markers to predict outcomes in non-compaction cardiomyopathy: a machine learning study.

AIMS: Left ventricular non-compaction cardiomyopathy (LVNC) is a genetic heart disease, with heart failure, arrhythmias, and embolic events as main clinical manifestations. The goal of this study was to analyse a large set of echocardiographic (echo) and cardiac magnetic resonance imaging (CMRI) parameters using machine learning (ML) techniques to find imaging predictors of clinical outcomes in a long-term follow-up of LVNC patients. METHODS AND RESULTS: Patients with echo and/or CMRI criteria of LVNC, followed from January 2011 to December 2017 in the heart failure section of a tertiary referral cardiologic hospital, were enrolled in a retrospective study. Two-dimensional colour Doppler echocardiography and subsequent CMRI were carried out. Twenty-four hour Holter monitoring was also performed in all patients. Death, cardiac transplantation, heart failure hospitalization, aborted sudden cardiac death, complex ventricular arrhythmias (sustained and non-sustained ventricular tachycardia), and embolisms (i.e. stroke, pulmonary thromboembolism and/or peripheral arterial embolism) were registered and were referred to as major adverse cardiovascular events (MACEs) in this study. Recruited for the study were 108 LVNC patients, aged 38.3 ± 15.5 years, 48.1% men, diagnosed by echo and CMRI criteria. They were followed for 5.8 ± 3.9 years, and MACEs were registered. CMRI and echo parameters were analysed via a supervised ML methodology. Forty-seven (43.5%) patients had at least one MACE. The best performance of imaging variables was achieved by combining four parameters: left ventricular (LV) ejection fraction (by CMRI), right ventricular (RV) end-systolic volume (by CMRI), RV systolic dysfunction (by echo), and RV lower diameter (by CMRI) with accuracy, sensitivity, and specificity rates of 75.5%, 77%, 75%, respectively. CONCLUSIONS: Our findings show the importance of biventricular assessment to detect the severity of this cardiomyopathy and to plan for early clinical intervention. In addition, this study shows that even patients with normal LV function and negative late gadolinium enhancement had MACE. ML is a promising tool for analysing a large set of parameters to stratify and predict prognosis in LVNC patients.

Is It Safe for Patients With Cardiac Channelopathies to Undergo Routine Dental Care? Experience From a Single-Center Study.

Background Brugada syndrome and long-QT syndrome may account for at least one third of unexplained sudden cardiac deaths. Dental care in patients with cardiac channelopathies is challenging because of the potential risk of life-threatening events. We hypothesized that the use of local dental anesthesia with lidocaine with and without epinephrine is safe and does not result in life-threatening arrhythmias in patients with channelopathies. Methods and Results We performed a randomized, double-blind pilot trial comparing the use of 2% lidocaine without a vasoconstrictor and with 1:100 000 epinephrine in 2 sessions of restorative dental treatment with a washout period of 7 days (crossover trial). Twenty-eight-hour Holter monitoring was performed, and 12-lead electrocardiography, digital sphygmomanometry, and anxiety scale assessments were also conducted at 3 time points. Fifty-six dental procedures were performed in 28 patients (18 women, 10 men) with cardiac channelopathies: 16 (57.1%) had long-QT syndrome, and 12 (42.9%) had Brugada syndrome; 11 (39.3%) of patients had an implantable defibrillator. The mean age was 45.9±15.9 years. The maximum heart rate increased after the use of epinephrine during the anesthesia period from 82.1 to 85.8 beats per minute (P=0.008). In patients with long-QT syndrome, the median corrected QT was higher, from 450.1 to 465.4 ms (P=0.009) at the end of anesthesia in patients in whom epinephrine was used. The other measurements showed no statistically significant differences. No life-threatening arrhythmias occurred during dental treatment. Conclusions The use of local dental anesthesia with lidocaine, regardless of the use of a vasoconstrictor, did not result in life-threatening arrhythmias and appears to be safe in stable patients with cardiac channelopathies. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT03182777.

Estudo Randomizado Comparando a Ablação por Cateter com o PVAC Gold vs. Tratamento com Fármacos Antiarrítmicos em Pacientes Idosos com Fibrilação Atrial Sintomática / Randomized Study Comparing Radiofrequency Ablation with the PVAC Gold System vs. Antiarrhythmic Drugs in Elderly Patients with Symptomatic Atrial Fibrillation

Resumo Fundamento Não existem estudos randomizados comparando a manutenção do ritmo sinusal após ablação por cateter (AC) em relação ao tratamento com fármacos antiarrítmicos (AA) em pacientes idosos portadores fibrilação atrial (FA) paroxística. Objetivos Comparar os resultados clínicos do isolamento das veias pulmonares (VPs) com o cateter PVAC Gold de segunda geração com o uso de AA em idosos com FA paroxística sintomática, recorrente, apesar do uso de fármacos AA. Métodos Sessenta pacientes com FA paroxística ≥ 65 anos e sem cardiopatias estruturais foram randomizados para duas formas de tratamento: grupo 1: AC e grupo 2: AA. O desfecho primário foi a taxa livre de recorrência de FA após pelo menos um ano de seguimento. Os desfechos secundários foram: progressão para formas persistentes de FA, impacto na qualidade de vida (QVFA) e complicações. O nível de significância adotado na análise estatística foi de 5% (p<0,05). Resultados A taxa livre de recorrência de FA foi de 80% (10% com amiodarona) no grupo AC, após 1,3 procedimentos por paciente e de 65% no grupo AA (60% com amiodarona), (p = 0,119) num seguimento médio de 719 dias (Q1: 566; Q3: 730). A taxa livre de FA persistente foi de 83,4% no grupo AC e de 67,7% no grupo AA (p = 0,073). Ambas as estratégias apresentaram melhora no escore de QVFA durante o seguimento (p < 0,001), sem diferença entre os grupos. Embora sem repercussão clínica ou impacto no teste de avaliação intelectual, 25% dos pacientes do grupo PVAC apresentou sinais de embolização cerebral na RNM cerebral. Conclusões Ambas as estratégias para manutenção do ritmo sinusal promoveram melhora na qualidade de vida de pacientes idosos com FA sintomática, sem diferença estatística nos desfechos clínicos preconizados. Estudos adicionais usando tecnologias com melhor perfil de segurança são necessários para avaliar os benefícios da AC em pacientes idosos com FA.

Abstract Background There are no randomized studies comparing the maintenance of sinus rhythm after catheter ablation (CA) concerning treatment with antiarrhythmic drugs (AA) in elderly patients with paroxysmal atrial fibrillation (AF). Objectives To compare the clinical results of pulmonary vein (PV) isolation with the second-generation PVAC Gold catheter against AA treatment in elderly people with recurrent symptomatic paroxysmal AF, refractory to at least one AA, and without structural heart disease. Methods Sixty patients with paroxysmal AF ≥ 65 years old were randomized to two forms of treatment: group 1: CA and group 2: AA drugs. The primary outcome was the AF recurrence-free rate after at least one year of follow-up. Secondary outcomes were: progression to persistent forms of AF, impact on quality of life (QOLF), and complications. The significance level adopted in the statistical analysis was 5% (p<0.05). Results The AF recurrence-free rate was 80% (10% with amiodarone) in the CA group, after 1.3 procedures per patient and 65% in the AA group (60% with amiodarone), (p = 0.119) in an average follow-up of 719 days (Q1: 566; Q3: 730). The persistent AF free rate was 83.4% in the AC group and 67.7% in the AA group (p = 0.073) Both strategies showed an improvement in the AFQoL score during follow-up (p < 0.001), with no difference between the groups. Although without clinical repercussions or impact on the intellectual assessment test, 25% of patients in the CA group showed signs of cerebral embolization on brain MRI. Conclusions Both strategies for maintaining sinus rhythm promoted an improvement in the quality of life of elderly patients with symptomatic AF, with no statistical difference in the clinical outcomes. Additional studies using technologies with a better safety profile are needed to evaluate the benefits of CA in elderly patients with AF.

Intramyocardial injection of autologous bone marrow cells as an adjunctive therapy to incomplete myocardial revascularization--safety issues.

OBJECTIVES: To determine the safety of intramyocardial injection of autologous bone marrow cells in patients undergoing surgical myocardial revascularization (CABG) for severe coronary artery disease. INTRODUCTION: There is little data available regarding the safety profile of autologous bone marrow cells injected during surgical myocardial revascularization. Potential risks include arrythmias, fibrosis in the injected sites and growth of non-cardiac tissues. METHODS: Ten patients (eight men) were enrolled; they were 59+/-5 years old with limiting angina and were non-optimal candidates for complete CABG. Bone marrow cells (1.3+/-0.3x10(8)) were obtained prior to surgery, and the lymphomonocytic fraction (CD34+ =1.8+/-0.3%) was separated by density gradient centrifugation. During surgery, bone marrow cells were injected in non-grafted areas of ischemic myocardium. During the first year after surgery, the patients underwent laboratory tests, cardiac imaging, and 24-hour ECG monitoring. RESULTS: Injected segments: inferior (n=7), anterior (n=2), septal (n=1), apical (n=1), and lateral (n=1) walls. Except for a transient elevation of C-reactive protein at one month post-surgery (P=0.01), laboratory tests results were within normal ranges; neither complex arrhythmias nor structural abnormalities were detected during follow-up. There was a reduction in functional class of angina from 3.6+/-0.8 (baseline) to 1.2+/-0.4 (one year) (P<0.0001). Also, patients had a significant decrease in the ischemic score assessed by magnetic resonance, not only globally from 0.65+/-0.14 (baseline) to 0.17+/-0.05 (one year) (P=0.002), but also in the injected areas from 1.11+/-0.20 (baseline) to 0.34+/-0.13 (one year) (P=0.0009). CONCLUSIONS: Intramyocardial injection of bone marrow cells combined with CABG appears to be safe. Theoretical concerns with arrhythmias and/or structural abnormalities after cell therapy were not confirmed in this safety trial.

Premature atrial and ventricular complexes in outpatients referred from a primary care facility.

BACKGROUND: Premature complexes are common electrocardiographic findings in daily clinical practice that require further evaluation. Investigation may sometimes be complex and expensive. The aim of our study was to analyze variables associated with premature beats identified in outpatients referred from a primary care facility. MATERIALS AND METHODS: We performed a cross-sectional study of 407 outpatients (aged 55.8±11years; 56% women) who were followed by general practitioners and were referred for resting 12-lead electrocardiograms for a routine clinical follow-up. After signing informed consent, patients answered a questionnaire and underwent physical examinations, laboratory diagnostics, transthoracic echocardiograms and 24-hour Holter monitoring to evaluate for the presence of premature complexes. After the univariate analyses, logistic regression analyses were performed with adjustment for age, sex, and cardiovascular diseases. RESULTS: Premature complexes distribution revealed that they were frequent but with low density. Premature atrial complexes (≥ 4/hours) were associated with age (Odds Ratio (OD) = 1.030, Confidence Interval (CI) 95% = 1.002 ─ 1.059, p = 0.029), brain natriuretic peptide (BNP) levels > 20mg/dL (OR = 4.489, 95%CI = 1.918 ─ 10.507, p = 0.0005), intraventricular blocks (OR = 4.184, 95%CI = 1.816 ─ 9.406, p = 0.0005) and left atrial diameter (OR = 1.065, 95%CI = 1.001 ─ 1.134, p = 0.046). Premature ventricular complexes (≥ 5/hour) were related to age (OR = 1.032, 95%CI = 1.010 ─ 1.054, p = 0.004), the use of calcium channel blockers (OR = 2.248, 95%CI = 1.019 ─ 4.954, p = 0.045), HDL-cholesterol levels (OR = 0.971, 95%CI = 0.951 ─ 0.992, p = 0.007), BNP levels > 20mg/dL (OR = 2.079, 95%CI = 0.991 ─ 0.998, p = 0.033), heart rate (OR = 1.019, 95%CI = 1.001 ─ 1.038, p = 0.041), left ventricular hypertrophy (OR = 2.292, 95%CI = 1.402 ─ 3.746, p = 0.001) and left ventricular ejection fraction (OR = 0.938, 95%CI = 0.900 ─ 0.978, p = 0.002). CONCLUSIONS: Premature complexes had low density and were associated with BNP levels > 20mg/dL, lower levels of HDL-cholesterol, left atrial enlargement and ventricular hypertrophy. The identification of premature complexes on 24-hour Holter monitor recordings of outpatients in a primary public healthcare setting was associated with uncontrolled cardiovascular risk factors that may be addressed with medical advice and therapy in a primary care setting.

Favorable Safety Experience of Local Dental Anesthesia in ICD Recipients with Cardiac Channelopathies

Abstract Background Dental anesthetic management in implantable cardioverter defibrillator (ICD) recipients with cardiac channelopathies (CCh) can be challenging due to the potential risk of life-threatening arrhythmias and appropriate ICD therapies during procedural time. Objectives The present study assessed the hypothesis that the use of local dental anesthesia with 2% lidocaine with 1:100,000 epinephrine or without a vasoconstrictor can be safe in selected ICD and CCh patients, not resulting in life-threatening events (LTE). Methods Restorative dental treatment under local dental anesthesia was made in two sessions, with a wash-out period of 7 days (cross-over trial), conducting with a 28h - Holter monitoring, and 12-lead electrocardiography, digital sphygmomanometry, and anxiety scale assessments in 3 time periods. Statistical analysis carried out the paired Student's t test and the Wilcoxon signed-rank test. In all cases, a significance level of 5% was adopted. All patients were in stable condition with no recent events before dental care. Results Twenty-four consecutive procedures were performed in 12 patients (9 women, 3 men) with CCh and ICD: 7 (58.3%) had long QT syndrome (LQTS), 4 (33.3%) Brugada syndrome (BrS), and 1 (8.3%) Catecholaminergic polymorphic ventricular tachycardia (CPVT). Holter analysis showed no increased heart rate (HR) or sustained arrhythmias. Blood pressure (BP), electrocardiographic changes and anxiety measurement showed no statistically significant differences. No LTE occurred during dental treatment, regardless of the type of anesthesia. Conclusion Lidocaine administration, with or without epinephrine, can be safely used in selected CCh-ICD patients without LTE. These preliminary findings need to be confirmed in a larger population with ICD and CCh.

Cardiac arrhythmias and atrioventricular block in a cohort of asymptomatic individuals without heart disease.

AIMS: To evaluate cardiac arrhythmias and rhythm disturbances on 24 h ambulatory electrocardiographic monitoring in a cohort of asymptomatic healthy individuals with normal clinical examination. METHODS AND RESULTS: 625 asymptomatic healthy individuals, in the age range 15-83 (mean 42, SD 11.9) years; 276 (44.2%) men and 349 (55.8%) women were submitted to 24-hour ambulatory electrocardiographic monitoring. Statistical analysis was performed with likelihood ratio test and automatic backward logistic regression. The frequency of atrial arrhythmias (p < 0.0001; OR 1.059; 95% CI 1.050-1068) and of ventricular arrhythmias (p < 0.0001; OR 1.023; 95% CI 1.017-1.029) increased for each age increase of 1 year; neither atrial nor ventricular arrhythmias demonstrated a statistically significant difference relative to gender. Transient second-degree atrioventricular block (Mobitz I) was observed in 14 (2.2%) individuals and was more frequent in individuals with resting heart rate <60 bpm (p = 0.006; OR 6.7, 95% CI 1.7-25.5). CONCLUSION: The frequency of atrial and ventricular arrhythmias increased with age and did not demonstrate a significant difference relative to gender. Transient atrioventricular block was more frequent in individuals with lower resting heart rate.

Lower heart rate variability is associated with higher serum high-sensitivity C-reactive protein concentration in healthy individuals aged 46 years or more.

BACKGROUND: To test the hypothesis of an association between cardiac autonomic activity evaluated by heart rate variability and systemic inflammatory markers such as C-reactive protein, we studied the correlation of the indices of heart rate variability relative to serum high-sensitivity C-reactive protein (hs-CRP) in a healthy Brazilian population. METHODS: Four hundred twenty-one healthy individuals aged 15-82 years (mean 40.4 years), 184 men (43.7%) and 237 women (56.3%) were enrolled between July 1998 and July 2001. The relationship between the log-transformed indices of the heart rate variability and the serum concentration of hs-CRP were analyzed stratified by age tertile using the Spearman correlation coefficient and multiple linear regression. RESULTS: The log standard deviation of all normal sinus RR intervals over 24 h (SDNN) (r = -0.801; p = 0.024) was independently correlated with log hs-CRP in the individuals with age in the oldest tertile (> or = 46 years). In addition, the body mass index (BMI) was independently correlated with hs-CRP in all of the age groups. CONCLUSIONS: In the healthy subjects aged 46 years or more the lower heart rate variability correlated with higher concentration of hs-CRP.

[QT interval dispersion analysis in acute myocardial infarction patients: coronary reperfusion effect]. / Análise da dispersão do intervalo QT em pacientes com infarto agudo do miocárdio: efeito da reperfusão coronariana.

OBJECTIVE: To study the effect of early reperfusion of infarct-related artery on QT(DeltaQT) dispersion interval, as well as how valuable it is as a marker for coronary reperfusion and ventricular arrhythmias. METHODS: One hundred and six patients with reperfusion (WR) and 48 without reperfusion (WtR) who have received thrombolytic therapy in the acute phase of infarction were studied. ECG carried out on admission as well as on day 4 of patients course were analyzed. DeltaQT - defined as the difference between maximum and minimum QT interval - was measured by 12-lead ECG. RESULTS: The reperfusion group showed significant DeltaQT reduction - from 89.66+/-20.47ms down to 70.95+/-21.65ms (p<0.001). On the other hand, the group without reperfusion showed DeltaQT significant increase - from 81.27+/-20.52ms up to 91.85+/-24.66ms (p<0.001). Logistic regression analysis showed that reduction magnitude between pre- and post-thrombolysis DeltaQT was the independent factor to most effectively identify coronary reperfusion (OR 1.045, p<0.0001; CI 95%). No significant difference was found in dispersion measures when patients with ventricular arrhythmias were compared with those with no arrhythmias in the course of the first 48 hours. CONCLUSION: The study shows that DeltaQT is significantly reduced in patients with acute myocardial infarction submitted to successful thrombolysis, and is increased in infarcted patients with closed artery. DeltaQT reduction between the pre- and post-thrombolysis condition was a predictor for coronary reperfusion of those patients, and did not show correlation to ventricular arrhythmias.

Reproducibility for Heart Rate Variability Analysis during 6-Min Walk Test in Patients with Heart Failure and Agreement between Devices.

Heart rate variability (HRV) analysis is a useful method to assess abnormal functioning in the autonomic nervous system and to predict cardiac events in patients with heart failure (HF). HRV measurements with heart rate monitors have been validated with an electrocardiograph in healthy subjects but not in patients with HF. We explored the reproducibility of HRV in two consecutive six-minute walk tests (6MW), 60-minute apart, using a heart rate monitor (PolarS810i) and a portable electrocardiograph (called Holter) in 50 HF patients (mean age 59 years, NYHA II, left ventricular ejection fraction ~35%). The reproducibility for each device was analysed using a paired t-test or the Wilcoxon signed-rank test. Additionally, we assessed the agreement between the two devices based on the HRV indices at rest, during the 6MW and during recovery using concordance correlation coefficients (CCC), 95% confidence intervals and Bland-Altman plots. The test-retest for the HRV analyses was reproducible using Holter and PolarS810i at rest but not during recovery. In the second 6MW, patients showed significant increases in rMSSD and walking distance. The PolarS810i measurements had remarkably high concordance correlation [0.86

Influence of age, gender, and serum triglycerides on heart rate in a cohort of asymptomatic individuals without heart disease.

BACKGROUND: Age, sex and blood lipids were demonstrated in epidemiological studies to influence heart rate measured on physical examination, on 12-lead electrocardiogram or with automatic devices for short-term measurements. We hypothesized that in healthy individuals, age, sex and other clinical variables may also influence heart rate measured on 24-h ambulatory electrocardiographic monitoring. METHODS: We studied 625 asymptomatic individuals with normal clinical examination, aged 15 to 83 (mean 42, standard deviation 11.9) years, 276 (44.2%) men and 349 (55.8%) women. Heart rate was evaluated on 24 h ambulatory electrocardiographic monitoring. Variables selected in univariate analysis (chi(2) and Student t tests) were further submitted to multivariate analysis with canonical correlation to assess the strength of associations between heart rate and other variables, and multiple linear regression models to generate reference curves. RESULTS: Age was the most significant influence on canonical variable of heart rate relative to other clinical and laboratory variables (0.55; p<0.01). There was an increase in the minimum heart rate and a decrease of maximum heart rate with increasing age in both genders. The increase was steeper in men and the decrease was steeper in women. Minimum heart rate increased with increasing serum triglycerides and decreased as estimated maximum oxygen consumption increased. CONCLUSIONS: There was a narrower variation of heart rate with increasing age in both genders in healthy individuals. This variation was less pronounced in women. In addition, status of body haemostasis associated with peculiar metabolic conditions expressed in serum triglycerides levels may also be associated with heart rate.

Dysregulation of Autonomic Nervous System in Chagas' Heart Disease Is Associated with Altered Adipocytokines Levels.

BACKGROUND: Chagas disease (CD) induces autonomic dysfunction and inflammatory activity, which may promote metabolic abnormalities. We studied metabolism and his correlation with Autonomic Nervous System (ANS) and inflammation in CD. METHODS AND RESULTS: Sixty subjects were divided into 4 groups: control group (CG), IF (indeterminate form) group; ECG group (ECG abnormalities and normal left ventricular systolic function), and LVD group (left ventricular sistolic dysfunction). Levels of adiponectin, leptin, insulin, interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) were assayed in serum samples by ELISA. ANS was assessed by heart rate variability in frequency domain in 24-hour Holter and postural tilt test (rest and orthostatic position). High frequency (HFr) component values were used to estimate parasympathetic activity and low frequency (LFr) component, sympathetic activity. Analyzes were made of the correlations of each of the metabolic parameters (leptin and adiponectin) with the inflammatory cytokines (interleukin-6 and TNF- alpha) and with the ANS assessment measurements. No significant differences were observed in leptin and insulin levels. Adiponectin was higher in ECG and LVD groups: [CG = 4766.5 (5529.5), IF = 4003.5 (2482.5), ECG = 8376.5 (8388.5), LVD = 8798 (4188.0) ng/mL, p<0.001)]. IL-6 and TNF-alpha were higher in LVD group: [IL-6: CG = 1.85 (6.41); IF = 1.58 (1.91); ECG = 1.0 (1.57); LVD= 31.44 (72.19) pg/ml; p = 0.001. TNF-alpha: CG = 22.57 (88.2); IF = 19.31 (33.16); ECG = 12.45 (3.07); LVD = 75.15 (278.57) pg/ml; p = 0.04]. Adiponectin levels had a positive association with the HFr component (r = 0.539; p = 0.038) and an inverse association with the LFr component (r = - 0.539; p = 0.038) in ECG group. Leptin levels had a negative association with the HFr component (r= - 0.632; p = 0.011) and a positive association with the LFr component (r = 0.632; p = 0.011) in LVD group. CONCLUSIONS: We found increased adiponectin levels in Chagas' heart disease with systolic dysfunction and in patients with ECG abnormalities and normal systolic function at rest. Adipocytokines levels (adiponectin and leptin) were associated with ANS parameters in Chagas' heart disease.

Influence of age, gender, body mass index, and functional capacity on heart rate variability in a cohort of subjects without heart disease.

We studied the time- and frequency-domain indexes of heart rate variability (HRV) in 653 patients without any evidence of heart disease relative to age, gender, heart rate, body mass index, and functional capacity. There was an inverse correlation of HRV with heart rate (p <0.001). HRV indexes decreased with increasing age, differed by gender, and were higher in patients with higher functional capacity. No correlation was noted between HRV and body mass index.

Electrocardiographic and blood pressure alterations during electroconvulsive therapy in young adults.

OBJECTIVE: To study cardiovascular alterations in young patients with no apparent organic disease who underwent electroconvulsive therapy. METHODS: The study comprised 47 healthy patients (22 males and 25 females) with a mean age of 30.3 years, who underwent electroconvulsive therapy. Ambulatory blood pressure monitoring and continuous electrocardiographic monitoring (Holter monitor) were performed during 24 hours. Blood pressure and heart rate were assessed 4 hours prior to electric shock administration, during electric shock administration, and 3 hours after electric shock administration. Arrhythmias and alterations in the ST segment in 24 hours were recorded. RESULTS: On electroconvulsive therapy, a significant increase in blood pressure and heart rate was observed and the measurements returned to basal values after 25 minutes. Three females had tracings with depression of the ST segment suggesting myocardial ischemia prior to and after electroconvulsive therapy. Coronary angiography was normal. No severe cardiac arrhythmias were diagnosed. CONCLUSION: 1) Electroconvulsive therapy is a safe therapeutic modality in psychiatry; 2) it causes a significant increase in blood pressure and heart rate; 3) it may be associated with myocardial ischemia in the absence of coronary obstructive disease; 4) electroconvulsive therapy was not associated with the occurrence of severe cardiac arrhythmias.

Late outcome of a randomized study on oral magnesium for premature complexes.

BACKGROUND: Ventricular and supraventricular premature complexes (PC) are frequent and usually symptomatic. According to a previous study, magnesium pidolate (MgP) administration to symptomatic patients can improve the PC density and symptoms. OBJECTIVE: To assess the late follow-up of that clinical intervention in patients treated with MgP or placebo. METHODS: In the first phase of the study, 90 symptomatic and consecutive patients with PC were randomized (double-blind) to receive either MgP or placebo for 30 days. Monthly follow-up visits were conducted for 15 months to assess symptoms and control electrolytes. 24-hour Holter was performed twice, regardless of symptoms, or whenever symptoms were present. In the second phase of the study, relapsing patients, who had received MgP or placebo (crossing-over) in the first phase, were treated with MgP according to the same protocol. RESULTS: Of the 45 patients initially treated with MgP, 17 (37.8%) relapsed during the 15-month follow-up, and the relapse time varied. Relapsing patients treated again had a statistically significant reduction in the PC density of 138.25/hour (p < 0.001). The crossing-over patients reduced it by 247/hour (p < 0.001). Patients who did not relapse, had a low PC frequency (3 PC/hour). Retreated patients had a 76.5% improvement in symptom, and crossing-over patients, 71.4%. CONCLUSION: Some patients on MgP had relapse of symptoms and PC, indicating that MgP is neither a definitive nor a curative treatment for late follow-up. However, improvement in the PC frequency and symptoms was observed in the second phase of treatment, similar to the response in the first phase of treatment.

Recommendations of the Brazilian Society of Cardiac Arrhythmias for holter monitoring services.

BACKGROUND: There are innumerous indicators to assure the quality of a service. However, medical competence and the proper performance of a procedure determine its final quality. The Brazilian Society of Cardiac Arrhythmias recommends minimum parameters necessary to guarantee the excellence of ambulatory electrocardiographic monitoring services. OBJECTIVE: To recommend minimum medical competences and the information required to issue a Holter monitoring report. METHODS: This study was grounded in the concept of evidence-based medicine and, when evidence was not available, the opinion of a writing committee was used to formulate the recommendation. That committee consisted of professionals with experience on the difficulties of the method and management in providing services in that area. RESULTS: The professional responsible for the Holter monitoring analysis should know cardiovascular pathologies and have consistent formation on electrocardiography, including cardiac arrhythmias and their differential diagnoses. The report should be written in a clear and objective way. The minimum parameters that comprise a Holter report should include statistics of the exam, as well as quantification and analysis of the rhythm disorders observed during monitoring. CONCLUSION: Ambulatory electrocardiographic monitoring should be performed by professionals knowledgeable about electrocardiographic analysis, whose report should comprise the minimum parameters mentioned in this document.