Congenital left ventricular diverticulum: A rare cause of cardiac arrhythmia.

Congenital left ventricular diverticula are rare cardiac malformations that usually remain asymptomatic. However, life-threatening complications as ventricular arrhythmias, systemic embolism, spontaneous rupture and development of valvular regurgitation, are described. Diagnosis is based on excluding coronary artery disease, traumatic or inflammatory causes, and other underlying cardiomyopathies. Treatment is directed towards the potential complications, yielding mainly therapy of ventricular arrhythmia. Surgical resection is required for larger-sized congenital aneurysms with adverse hemodynamic effects. We present two cases of a left ventricular diverticulum causing cardiac arrhythmia which led to further surgical treatment.

Evaluation of a simple technique aiming at optimizing point-by-point isolation of the left pulmonary veins: a randomized study.

AIMS: We sought to evaluate the efficacy and the safety of a simple technique for stabilizing the ablation catheter during anterior pulmonary vein (PV) encirclement in patients ablated for paroxysmal atrial fibrillation. This consisted of bending the ablation catheter in the left atrium, creating a loop that was cautiously advanced together with the long sheath at the ostium and then within the left superior PV. The curve was then progressively released to reach a stable contact with the anterior part of the left PVs. METHODS AND RESULTS: Eighty consecutive patients (age 64 ± 11 years, left atrial diameter 43 ± 8 mm) undergoing 'CLOSE'-guided PV isolation were prospectively randomized into two groups depending on whether the loop technique was used or not. When using the loop technique, the encirclement of the left PVs was shorter [20 min (interquartile range, IQR 17-24) vs. 26 min (IQR 18-33), P < 0.01] with a high rate of first pass isolation [(100%) vs. (97%), P = 0.9] and adenosine proof isolation [(93%) vs. (95%), P = 0.67]. Most specifically, at the anterior part of the left PVs, there were less dislocations [0 (IQR 0-0) vs. 1 (IQR 0-4), P < 0.001], radiofrequency duration was shorter (272 ± 85 s vs. 378 ± 122 s, P < 0.001), force-time integral was higher [524 gs (IQR 427-687) vs. 398 gs (IQR 354-451), P < 0.001], average contact force was higher [20 g (IQR 13-27) vs. 11g (IQR 9-16), P < 0.001], and impedance drop was higher [12 Ω (IQR 9-19) vs. 10 Ω (IQR 7-14), P < 0.001]. CONCLUSION: This study describes a simple technique to facilitate catheter stability at the anterior part of the left PVs, resulting in more efficient left PV encirclement without compromising safety.

Evaluation of left atrial linear ablation using contiguous and optimized radiofrequency lesions: the ALINE study.

Aims: Achieving block across linear lesions is challenging. We prospectively evaluated radiofrequency (RF) linear ablation at the roof and mitral isthmus (MI) using point-by-point contiguous and optimized RF lesions. Methods and results: Forty-one consecutive patients with symptomatic persistent AF underwent stepwise contact force (CF)-guided catheter ablation during ongoing AF. A single linear set of RF lesions was delivered at the roof and posterior MI according to the 'Atrial LINEar' (ALINE) criteria, i.e. point-by-point RF delivery (up to 35 W) respecting strict criteria of contiguity (inter-lesion distance ≤ 6 mm) and indirect lesion depth assessment (ablation index ≥550). We assessed the incidence of bidirectional block across both lines only after restoration of sinus rhythm. After a median RF time of 7 min [interquartile range (IQR) 5-9], first-pass block across roof lines was observed in 38 of 41 (93%) patients. Final bidirectional roof block was achieved in 40 of 41 (98%) patients. First-pass block was observed in 8 of 35 (23%) MI lines, after a median RF time of 8 min (IQR 7-12). Additional endo- and epicardial (54% of patients) RF applications resulted in final bidirectional MI block in 28 of 35 (80%) patients. During a median follow-up of 396 (IQR 310-442) days, 12 patients underwent repeat procedures, with conduction recovery in 4 of 12 and 5 of 10 previously blocked roof lines and MI lines, respectively. No complications occurred. Conclusion: Anatomical linear ablation using contiguous and optimized RF lesions results in a high rate of first-pass block at the roof but not at the MI. Due to its complex 3D architecture, the MI frequently requires additional endo- and epicardial RF lesions to be blocked.

Changes in P-wave area and P-wave duration after circumferential pulmonary vein isolation.

AIMS: The effect of circumferential pulmonary vein isolation (CPVI) on P-wave characteristics is not clear. We used the signal-averaged (SA) electrocardiogram (ECG) and the ECG derived vector cardiogram (dVCG) to study the influence of CPVI on P-wave duration (PWD) and P-wave area (PWA) and studied whether changes were associated with successful outcome after initial CPVI. METHODS AND RESULTS: Thirty-nine patients (56 +/- 10 years, 72% males) underwent CPVI for paroxysmal or persistent atrial fibrillation (AF). For each patient, an ECG recording was taken at the start and end of the ablation procedure. dVCG was derived using the inverse Dower transform. PWD was defined by manual annotation of earliest onset and latest offset of the SA-P-wave. PWA was calculated as the area under the SA-ECG curve averaged for the 12 ECG leads (PWA-ECG) and SA-dVCG curve (PWA-dVCG). Successful outcome after CPVI was defined as freedom from symptomatic and asymptomatic AF at the end of follow-up (11 +/- 5 months). Average PWD decreased from 132 +/- 14 to 126 +/- 16 ms (P < 0.01). PWA-ECG and PWA-dVCG decreased markedly from 4.64 +/- 1.40 to 3.65 +/- 1.61 mVms (P < 0.001) and from 4.27 +/- 1.66 to 2.48 +/- 1.59 mVms (P < 0.001). Parameters of PWA were not different between successes (n = 31) and failures (n = 8). In contrast, PWD after ablation was significantly shorter in patients with successful outcome (123 +/- 16 vs. 135 +/- 11 ms, P < 0.05). CONCLUSION: (i) CPVI results in a modest but significant shortening in PWD and a marked decrease in PWA. (ii) PWD was significantly shorter in cases of successful outcome after CPVI.

Expanding the phenotype of sudden cardiac death-An unusual presentation of a family with a Lamin A/C mutation.

Familial occurrence of sudden cardiac death (SCD) is related to a variety of clinical conditions, which can be delineated in up to 40% of families through a combination of cardiovascular examination and genetic studies. Patients with Lamin A/C gene mutations are at increased risk for SCD, but "laminopathies" are not included into clinical algorithms of SCD. Here we present a family with SCD in the absence of left ventricular dysfunction, related to a Lamin A/C mutation.

Electrical storm in a patient with dilated non-ischaemic cardiomyopathy.

Bundle-branch re-entrant ventricular tachycardia (BBRVT) is usually seen in patients with dilated cardiomyopathy. The diagnosis should be suspected in case the QRS morphology during the tachycardia is identical to that in sinus rhythm. Identifying patients with BBRVT is important because they can be easily treated by catheter ablation. This report describes a patient previously implanted with a cardiac resynchronization therapy defibrillator (CRT-D) presenting with an electrical storm due to BBRVT.

Incidence, timing, and characteristics of acute changes in heart rate during ongoing circumferential pulmonary vein isolation.

AIMS: Previous studies showed that catheter ablation of atrial fibrillation (AF) results in vagal denervation with an increase in average heart rate (HR) and a reduced overall HR variability (HRV) at follow-up. We analysed acute ablation-induced changes in HR and short-term HRV during percutaneous circumferential pulmonary vein isolation (CPVI). We also studied whether observed changes were predictors of successful outcome after first CPVI. METHODS AND RESULTS: A total of 46 patients (35 men, 55 +/- 10 years) undergoing CARTO and computed tomography-guided CPVI for symptomatic AF were studied. Circumferential pulmonary vein isolation was performed under general anaesthesia by widely encircling the left and right pulmonary veins during sinus rhythm (SR). Radiofrequency (RF) current (35W, 48 degrees C) was applied with a 3.5 mm open irrigated tip catheter (Navistar Thermocool, Biosense Webster, Diamond Bar, CA, USA). Time- and frequency-domain analysis of short-term HRV was performed using 5 min electrocardiogram (ECG) recordings obtained at the beginning and the end of the CPVI procedure. Sinus rhythm cycle length was monitored continuously during CPVI. Circumferential pulmonary vein isolation was performed with 119 +/- 25 RF applications. Mean HR increased from 54 +/- 8 to 62 +/- 9 bpm (P < 0.001). Heart rate variability was significantly reduced (SDNN from 34 +/- 30 ms to 14 +/- 17 ms, P < 0.001, RMSSD from 27 +/- 22 ms to 13 +/- 14 ms, P < 0.001) with a marked change in sympathovagal balance towards less vagal activity (low frequency (LF)/high frequency (HF) ratio from 3.94 +/- 0.33 to 4.20 +/- 0.17, P < 0.001). Changes in RR interval, SDNN, and LF/HF ratio correlated significantly with RR interval (R = 0.56, P < 0.001), SDNN (R = 0.84, P < 0.001), and LF/HF ratio (R = -0.74, P < 0.001) at baseline. There were acute changes during ablation in HR and HRV, at the antero-superior junction between the left atrium (LA) and the right superior pulmonary vein (RSPV) in 36 patients (78%). Both HR and HRV at baseline and changes in HR/HRV were comparable between successful (n = 36) and failed (n = 10) patients. CONCLUSION: (i) Percutaneous CPVI induces acute acceleration of HR and attenuation of short-term HRV (indicating vagal denervation during the procedure). (ii) Acute changes in HR and its variability invariably occur during RF energy delivery at the antero-superior junction between the LA and the RSPV. (iii) The degree of HR and short-term HRV changes depend on the vagal tone at the beginning of the procedure. (iv) In contrast to previously reported changes in overall HRV, acute changes in HR during the procedure are no predictors of long-term clinical outcome after CPVI.

Ablation of an idiopathic left ventricular tachycardia originating from the posterior mitral annulus in a toddler.

Ablation of a mitral annulus (MA)-ventricular tachycardia (VT), a rare form of idiopathic left VT, has not yet been described in patients <2 years of age. We describe a case of a toddler with an incessant, poorly tolerated idiopathic VT (190 bpm) refractory to medical therapy, which was successfully ablated in the left ventricle at the infero-posterior part of the MA. Different diagnostic and ablation steps are described. Mitral annulus-ventricular tachycardia, a rare form of idiopathic left VT, can safely and successfully be ablated in very young children.

Intra- and interatrial asynchrony in patients with heart failure.

Heart failure (HF) is associated with atrial conduction delay. Color tissue Doppler imaging was used to evaluate intra- and interatrial asynchrony in patients with HF, patients with structural heart disease without HF, and controls. Twenty-three controls (mean age 65 +/- 13 years), 29 patients with structural heart disease without HF (mean age 68 +/- 9 years), and 29 patients with HF (mean age 67 +/- 9 years) were studied. Patients had no histories of atrial fibrillation. Echocardiographic color tissue Doppler imaging of the atria was performed. Measurements below the atrioventricular plane were selected on the right atrial (RA) free wall, interatrial septum (IAS), and left atrial (LA) free wall. The time difference from the onset of the P wave to the onset of the A wave at the right atrium (P-RA), the IAS (P-IAS), and the left atrium (P-LA) was measured. Asynchrony was defined as the differences between P-IAS and P-RA (RA asynchrony), P-LA and P-IAS (LA asynchrony), and P-LA and P-RA (interatrial asynchrony). In patients with HF, a significant increase in RA asynchrony was observed compared with controls and patients without HF (30 +/- 21 vs 12 +/- 13 and 14 +/- 15 ms, p <0.001). LA asynchrony was not different (19 +/- 26 vs 25 +/- 13 vs 25 +/- 14 ms, p = NS). Interatrial asynchrony was significantly increased in patients with HF (49 +/- 24 vs 37 +/- 9 and 39 +/- 17 ms, p = 0.04). There were moderate but significant correlations of RA asynchrony with log N-terminal-pro-B-type natriuretic peptide (r = 0.3, p = 0.01) and the ejection fraction (r = -0.4, p <0.001). In conclusion, in patients with HF, significant RA and interatrial asynchrony was documented, evaluated by noninvasive color tissue Doppler imaging. Asynchrony was related to N-terminal-pro-B-type natriuretic peptide and to the ejection fraction.