Practical stepwise approach to rhythm disturbances in congenital heart diseases

Patients with congenital heart diseases (CHD) are confronted with early- and late-onset complications, such as conduction disorders, arrhythmias, myocardial dysfunction, altered coronary flow, and ischemia, throughout their lifetime despite successful hemodynamic and/or anatomical correction. Rhythm disturbance is a well-known and increasingly frequent cause of morbidity and mortality in patients with CHD. Predisposing factors to rhythm disturbances include underlying cardiac defects, hemodynamic changes as part of the natural history, surgical repair and related scarring, and residual hemodynamic abnormalities. Acquired factors such as aging, hypertension, diabetes, obesity, and others may also contribute to arrhythmogenesis in CHD. The first step in evaluating arrhythmias in CHD is to understand the complex anatomy and to find predisposing factors and hemodynamic abnormalities. A practical stepwise approach can lead to diagnosis and prompt appropriate interventions. Electrophysiological assessment and management should be done with integrated care of the underlying heart defects and hemodynamic abnormalities. Catheter ablation and arrhythmia surgery have been increasingly applied, showing increasing success rates with technological advancement despite complicated arrhythmia circuits in complex anatomy and the difficulty of access. Correction of residual hemodynamic abnormalities may be critical in the treatment of arrhythmia in patients with CHD

Perinatal changes in fetal ventricular geometry, myocardial performance and cardiac function in normal term pregnancies.

Background: The fetal heart at term is exposed to an increase in hemodynamic work as a consequence of fetal growth, increased circulating volume and alteration in loading patterns due to maturational changes in fetoplacental circulation. The extent to which these cardiovascular changes influence the human fetal and neonatal cardiac adaptation has not been fully elucidated. The aim of this study was to evaluate perinatal cardiovascular changes in ventricular geometry and myocardial performance in normal term fetuses. Methods: Prospective study of 108 uncomplicated pregnancies delivering at term. M-mode, twodimensional (2D) or B-mode, pulsed wave (PW) Doppler, PW tissue Doppler and 2D speckle tracking imaging were performed a few days before, and within 24 hours of birth. Results: Analysis of paired fetal and neonatal echoes demonstrated significant perinatal changes (p<0.0001 for all) in right ventricular (RV) and left ventricular (LV) geometry (RV/LV enddiastolic dimension ratio: 1.2 vs. 0.8, RV sphericity index: 0.53 vs. 0.40, LV sphericity index: 0.46 vs. 0.49). There were corresponding significant (p<0.001 for all) perinatal changes in global myocardial performance: LV myocardial performance index (MPI’): 0.60 vs. 0.47, RV MPI’: 0.61 vs. 0.42; systolic function: LV longitudinal systolic strain rate: -1.4 /s vs. -1.0 /s, RV longitudinal systolic strain rate: -1.5 /s vs. -1.0 /s; RV systolic annular peak velocity (S’): 5.3 cm/s vs. 6.5 cm/s; and diastolic function: LV diastolic annular peak velocity ratio (E’/A’): 0.8 vs.1.1. Conclusion: The findings support the concept that the perinatal period is associated with major changes in fetal ventricular geometry and cardiac function in response to significant alterations in loading conditions. Improved knowledge of perinatal cardiac changes in normal fetuses could facilitate better understanding of cardiac adaptation in normal and pathological pregnancies

Preoperative predictors of death and sustained ventricular tachycardia after pulmonary valve replacement in patients with repaired tetralogy of fallot enrolled in the INDICATOR Cohort

Background -Risk factors for adverse clinical outcomes have been identified in patients with repaired tetralogy of Fallot (rTOF) before pulmonary valve replacement (PVR). However, pre-PVR predictors for post-PVR sustained ventricular tachycardia (VT) and death have not been identified. Methods -Patients with rTOF enrolled in the INDICATOR cohort-a 4-center international cohort study- who had a comprehensive preoperative evaluation and subsequently underwent PVR were included. Pre-procedural clinical, electrocardiogram, cardiovascular magnetic resonance (CMR), and postoperative outcome data were analyzed. Cox proportional hazards multivariable regression analysis was used to evaluate factors associated with time from pre-PVR CMR until the primary outcome-death, aborted sudden cardiac death, or sustained VT. Results -Of the 452 eligible patients (median age at PVR 25.8 years), 36 (8%) reached the primary outcome (27 deaths, 2 resuscitated death, and 7 sustained VT) at a median time after PVR of 6.5 years. Cox proportional hazards regression identified pre-PVR right ventricular (RV) ejection fraction < 40% (hazard ratio [HR] 2.39; 95% confidence interval [CI] 1.18 to 4.85; P = 0.02), RV mass-to-volume ratio ≥ 0.45 g/mL (HR 4.08; 95%, CI 1.57 to 10.6; P = 0.004), and age at PVR ≥ 28 years (HR 3.10; 95% CI 1.42 to 6.78; P = 0.005) as outcome predictors. In a subgroup analysis of 230 patients with Doppler data, predicted RV systolic pressure ≥40 mm Hg was associated with the primary outcome (HR 3.42; 95% CI 1.09 to 10.7; P = 0.04). Preoperative predictors of a composite secondary outcome-postoperative arrhythmias and heart failure-included older age at PVR, pre-PVR atrial tachyarrhythmias, and a higher left ventricular end-systolic volume index. Conclusions -In this observational investigation of patients with rTOF, an older age at PVR and pre-PVR RV hypertrophy and dysfunction were predictive of shorter time to postoperative death and sustained VT. These findings may inform the timing of PVR if confirmed by prospective clinical trials

Hypoalbuminaemia predicts outcome in adult patients with congenital heart disease

Background In patients with acquired heart failure, hypoalbuminaemia is associated with increased risk of death. The prevalence of hypoproteinaemia and hypoalbuminaemia and their relation to outcome in adult patients with congenital heart disease (ACHD) remains, however, unknown. Methods Data on patients with ACHD who underwent blood testing in our centre within the last 14 years were collected. The relation between laboratory, clinical or demographic parameters at baseline and mortality was assessed using Cox proportional hazards regression analysis. Results A total of 2886 patients with ACHD were included. Mean age was 33.3 years (23.6–44.7) and 50.1% patients were men. Median plasma albumin concentration was 41.0 g/L (38.0–44.0), whereas hypoalbuminaemia (<35 g/L) was present in 13.9% of patients. The prevalence of hypoalbuminaemia was significantly higher in patients with great complexity ACHD (18.2%) compared with patients with moderate (11.3%) or simple ACHD lesions (12.1%, p<0.001). During a median follow-up of 5.7 years (3.3–9.6), 327 (11.3%) patients died. On univariable Cox regression analysis, hypoalbuminaemia was a strong predictor of outcome (HR 3.37, 95% CI 2.67 to 4.25, p<0.0001). On multivariable Cox regression, after adjusting for age, sodium and creatinine concentration, liver dysfunction, functional class and disease complexity, hypoalbuminaemia remained a significant predictor of death. Conclusions Hypoalbuminaemia is common in patients with ACHD and is associated with a threefold increased risk of risk of death. Hypoalbuminaemia, therefore, should be included in risk-stratification algorithms as it may assist management decisions and timing of interventions in the growing ACHD population

Automatic External Defibrillators: the Potential for Widespread Prevention of Sudden Cardiac Death in the Community

The vast majority of witnessed sudden cardiac death is due to the unpredictable occurrence of ventricular fibrillation, which is almost uniformly reversed by the immediate application of defibrillation. Thus, there is dire need for development of the appropriate conditions for early defibrillation in places where the likelihood of an unexpected sudden death event is deemed probable. In this setting, the automatic external defibrillators (AED) in the hands of even trained lay persons has been considered to have the potential to be the single greatest advance in the treatment of cardiac arrest due to ventricular fibrillation since the development of cardiopulmonary resuscitation. Several studies suggest that the use of publicly accessible AEDs by lay persons is feasible and that organized AED training should also focus on community and on-site responders. The potential for widespread prevention of sudden cardiac death in the community with the use of AEDs is discussed in this brief overview

Achievement of Right Ventricular Pacing by Use of a Long Guiding Catheter in a Hemodialysis Patient Presenting Significant Tortuosity of Vasculature

Increased vascular calcification and tortuosity are rather common in end-stage renal failure patients who are on hemodialysis. It renders manipulation of catheters and performance of percutaneous transluminal interventions more difficult than expected. Such vascular alterations may be evident in large veins and pose significant difficulties in placement of pacing leads as shown in our case. To overcome such difficulties, we demonstrated in this patient case that long guiding catheters may be of particular value