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Background: Myocardial crypts are discrete clefts or fissures in otherwise compacted myocardium of the left ventricle (LV). Recent reports suggest a higher prevalence of crypts in patients with hypertrophic cardiomyopathy (HCM) and also within small samples of genotype positive but phenotype negative relatives. The presence of a crypt has been suggested to be a predictor of gene carrier status. However, the prevalence and clinical significance of crypts in the general population is unclear. We aimed to determine the prevalence of myocardial crypts in a large cohort of subjects using clinical cardiovascular magnetic resonance (CMR)., Methods: Consecutive subjects referred for clinical CMR during a 12-month period (n = 1020, age 52.6 ± 17, males: 61%) were included. Crypts were defined as >50% invagination into normal myocardium and their overall prevalence, location and shape was investigated and compared between different patient groups., Results: The overall prevalence of crypts was 64/1020 (6.3%). In a predefined 'normal' control group the prevalence was lower (11/306, 3.6%, p = 0.031), but were equally prevalent in ischemic heart disease (12/236, 5.1%, p = n/s) and the combined non-ischemic cardiomyopathy (NICM) groups (24/373; 6.4%, p = n/s). Within the NICM group, crypts were significantly more common in HCM (9/76, 11.7%, p = 0.04) and hypertensive CM subjects (3/11, 27%, p = 0.03). In patients referred for CMR for family screening of inherited forms of CM, crypts were significantly more prevalent (10/41, 23%, p < 0.001), including a smaller group with a first degree relative with HCM (3/9, 33%, p = 0.01)., Conclusion: Myocardial crypts are relatively common in the normal population, and increasingly common in HCM and hypertensive cardiomyopathy. Crypts are also more frequently seen in normal phenotype subjects referred because of a family history of an inherited cardiomyopathy and HCM specifically. It is uncertain what the significance of crypts are in this group, and because of variability in the imaging protocols used and their relative frequency within the normal population, should not be used to clinically stratify these patients. Prospective studies are required to confirm the clinical significance of myocardial crypts, as their significance remains unclear.

Background: The classification of atrial fibrillation as paroxysmal or persistent (PsAF) is clinically useful, but does not accurately reflect the underlying pathophysiology and is therefore a suboptimal guide to selection of ablation strategy., Aim: To determine if additional substrate ablation is beneficial for a subset of patients with PsAF, in whom long periods of sinus rhythm (SR) can be maintained., Methods: We included patients presenting with PsAF in whom continuous periods of SR>3months were documented. All patients were in SR on the day of the procedure. Electrical pulmonary vein isolation (PVI) was performed in all patients. Additional electrogram (EGM)-guided ablation was left to the discretion of the operator. Patient characteristics and follow-up were analysed with respect to presence or absence of additional EGM-guided ablation., Results: Sixty-five patients (mean age 60.1±8.9years; 81.5% men) met the inclusion criteria. EGM-guided ablation was performed in 32 (49%) patients. Patients with and without EGM-guided ablation had similar baseline characteristics. Absence of EGM-guided ablation was one of the independent predictors for arrhythmia recurrences after the index procedure (hazard ratio 0.24; confidence interval 0.12-0.47). After a median follow-up of 18±10months, the number of procedures required was significantly higher in the 'PVI-only' group (2.24±0.75 vs. 1.84±0.81; P=0.04) to achieve a similar success rate (84% vs. 81%; P=0.833)., Conclusion: The addition of EGM-guided ablation requires fewer procedures to achieve similar clinical efficacy in mid-term follow-up compared with a PVI-only strategy in patients with PsAF presenting for ablation in SR., (Copyright © 2013. Published by Elsevier Masson SAS.)

Background: Pulmonary vein reconnection after pulmonary vein isolation is common and is usually associated with recurrences of atrial fibrillation. We used cardiac magnetic resonance imaging after radiofrequency ablation to investigate the hypothesis that acute pulmonary vein isolation results from a combination of irreversible and reversible atrial injury., Methods and Results: Delayed enhancement (DE; representing areas of acute tissue injury/necrosis) and T2-weighted (representing tissue water content, including edema) cardiac magnetic resonance scans were performed before, immediately after (acute), and later than 3 months (late) after pulmonary vein isolation in 25 patients with paroxysmal atrial fibrillation undergoing wide-area circumferential ablation. Images were analyzed as pairs of pulmonary veins to quantify the percentage of circumferential antral encirclement composed of DE, T2, and combined DE+T2 signal. Fourteen of 25 patients were atrial fibrillation free at 11-month follow-up (interquartile range, 8-16 months). These patients had higher DE (71±6.0%) and lower T2 signal (72±7.8%) encirclement on the acute scans compared with recurrences (DE, 55±9.1%; T2, 85±6.3%; P<0.05). Patients maintaining sinus rhythm had a lesser decline in DE between acute and chronic scans compared with recurrences (71±6.0% and 60±5.8% versus 55±9.1% and 34±7.3%, respectively). The percentage of encirclement by a combination of DE+T2 was almost similar in both groups on the acute scans (atrial fibrillation free, 89±5.4%; recurrences, 92±4.8%) but different on the chronic scans (60±5.7% versus 34±7.3%)., Conclusions: The higher T2 signal on acute scans and greater decline in DE on chronic imaging in patients with recurrences suggest that they have more reversible tissue injury, providing a potential mechanism for pulmonary vein reconnection, resulting in arrhythmia recurrence.