Search

Background There is increasing evidence that the Brugada ECG pattern is a marker of subtle structural heart disease. Objective The purpose of this study was to characterize patients with Brugada syndrome (BrS) using cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE). Methods BrS was diagnosed according to international guidelines. Twenty-six percent of patients with BrS carried SCN5A mutations. CMR data from 78 patients with BrS were compared with 78 healthy controls (44 ± 15 vs 42 ± 14 years; P = .434; and 64% vs 64% male; P = 1). Results Right ventricular (RV) ejection fraction was slightly lower (61 ± 8% vs 64 ± 5%; P = .004) and RV end-systolic volume slightly greater (31 ± 10 mL/m2 vs 28 ± 6 mL/m2; P = .038) in BrS compared with controls. These values remained within the normal range. LGE was demonstrated in 8% of patients with BrS (left ventricular midwall LGE in 5%) but not in controls (P = .028). In patients with BrS with midwall LGE there were no other features of cardiomyopathy at the time of CMR, but genetic testing and follow-up revealed a desmoplakin mutation in 1 patient and evolution of T-wave inversion throughout all precordial ECG leads in another. Neither patient fulfils diagnostic criteria for arrhythmogenic right ventricular cardiomyopathy. Conclusion Some patients with BrS have left ventricular midwall LGE consistent with an underlying cardiomyopathic process. Even cases without LGE show greater RV volumes and reduced RV function. These findings lend further support to the presence of subtle structural abnormalities in BrS. The BrS pattern with LGE may serve as early markers for evolution of a cardiomyopathic phenotype over time. CMR is a potentially useful adjunct investigation in the clinical evaluation of BrS.

About 4% of African Americans possess the isoleucine 122 (V122I) variant of transthyretin, associated with cardiac amyloidosis beyond ages of 55 to 60 years. Transthyretin amyloidosis associated with variant V122I (ATTR V122I) is likely to be an important cause of heart failure in Afro-Caribbean populations, but the high prevalence of left ventricular hypertrophy (LVH) and lack of awareness of this genetic disorder pose diagnostic hurdles. We report the electrocardiographic (ECG) features of ATTR V122I in the largest clinical series to date.Patients with ATTR V122I were identified in collaboration with the UK National Amyloidosis Centre. The ECG at presentation was assessed for cardiac rhythm, axis, and voltage complex size.We include 64 patients with ATTR V122I, with a median age of 74 years (range, 57-88 years). Normal or increased ECG voltage was present in 44.3% of patients, and overall 25% met the criteria for LVH. A significant negative correlation between voltage complex size and duration of illness was seen (P.05). First-degree heart block was evident in 56% of patients in sinus rhythm. During follow-up (n = 17; median, 28 months), 50% of patients with initial first-degree heart block required pacing.Electrocardiographic voltages meet the criteria for LVH in one quarter of patients with ATTR V122I cardiac amyloidosis. The widely held belief that cardiac amyloidosis is associated with low-voltage complexes is likely to contribute to underdiagnosis of ATTR V122I. First-degree heart block is common at diagnosis and identifies patients at high risk for subsequent pacing requirement.

ObjectivesThe complexity of aortic disease is not fully exposed by aortic dimensions alone, and morbidity or mortality can occur before intervention thresholds are met. Patient-specific computational fluid dynamics (CFD) was used to assess effect of different aortic valve morphologies on velocity profiles, flow patterns, helicity, wall shear stress (WSS) and oscillatory shear index (OSI) in the thoracic aorta.Methods45 subjects were divided into 5 groups: Volunteers, AR-TAV, AS-TAV, AS-BAV(RL), AS-BAV(RN), where AR=aortic regurgitation, AS=aortic stenosis, TAV=tricuspid aortic valve, BAV=bicuspid aortic valve, RL=right-left cusp fusion, RN=right-non cusp fusion. Subjects underwent magnetic resonance angiography, with phase-contrast MRI at the sino-tubular junction to define patient-specific inflow velocity profiles. Hemodynamic recordings were used alongside MRI angiographic data to run patient-specific CFD.ResultsBAV groups had larger mid-ascending aorta diameters (pasymmetry=78.9±6.5% for AS-BAV(RN), compared to 4.7±2.1% for Volunteers, p2, compared to 9.8±5.4 for Volunteers, pConclusionsBAV displays eccentric flow with high helicity. Presence of AS, particularly in BAV-RN led to higher WSS and lower OSI in the greater curvature of the ascending aorta. Patient-specific CFD provides non-invasive functional assessment of the thoracic aorta, and may enable development of a personalized approach to diagnosis and management of aortic disease beyond traditional guidelines.

We thank Barison et al. for their interest in our paper [(1)][1]. Cardiac amyloidosis is gaining significant exposure in the cardiac magnetic resonance (CMR) community because of the characteristic and near pathognomonic findings with the technique. We reported the first study that specifically

BACKGROUND: Physiological shortening of the atrioventricular (AV) interval with increasing heart rate is well documented in normal human beings and is an established component of dual-chamber pacing for bradycardia. OBJECTIVES: To assess the effect of exercise on optimal AV delay and the impact of a patient-specific rate-adaptive AV delay (RAAVD) on exercise capacity in patients with heart failure following cardiac resynchronization therapy. METHODS: Phase 1: We performed iterative AV optimization at rest and exercise in 52 cardiac resynchronization therapy patients in atrial-sensed mode (mean age 71.6 ± 9.2 years, 25% females). Phase 2: Subsequently, 20 consecutive volunteers from this group (mean age 69.2 ± 9.6 years, 15% females) underwent cardiopulmonary exercise testing with RAAVD individually programmed ON (RAAVD-ON) or OFF (RAAVD-OFF). RESULTS: Phase 1: In 94% of the patients, there was a marked reduction (mean 50%) in optimal AV delay with exercise. The optimal resting vs exercise AV delay was 114.2 ± 29 ms at a heart rate of 64.4 ± 7.1 beats/min vs 57 ± 31 ms at a heart rate of 103 ± 13 beats/min (P < .001). No patients required an increase in AV delay with exercise, and 3 (6%) showed no change. Phase 2: With RAAVD-ON, significantly better exercise times were achieved (8.7 ± 3.2 minutes) compared with RAAVD-OFF (7.9 ± 3.2 minutes; P = .003), and there was a significant improvement in Vo(2)max (RAAVD-ON 16.1 ± 4.0 vs RAAVD-OFF 14.9 ± 3.7 mL/(kg · min); P = .024). CONCLUSIONS: There was a dramatic reduction in optimal AV delay with physiological exercise in the majority of this heart failure cardiac resynchronization therapy cohort. Replicating this physiological response with a programmable RAAVD translated into a 10% improvement in exercise capacity.