Three-dimensional speckle tracking echocardiography allows detailed evaluation of left atrial function in hypertrophic cardiomyopathy--insights from the MAGYAR-Path Study.

INTRODUCTION: Hypertrophic cardiomyopathy (HCM) represents a generalized myopathic process affecting both ventricular and atrial myocardium. Reduced left atrial (LA) function was demonstrated in HCM by different methods. Three-dimensional (3D) speckle tracking echocardiography (STE) has just been introduced for the evaluation of LA. This study was designed to compare 3DSTE-derived LA volumetric and strain parameters in HCM with healthy controls. METHODS: The study comprised 23 consecutive HCM patients (mean age: 48.5 ± 15.1 years, 14 men). Their results were compared to 23 age- and gender-matched healthy controls. Complete two-dimensional Doppler echocardiography and 3DSTE have been performed in all cases. RESULTS: Calculated LA maximum (66.4 ± 20.4 mL vs. 36.0 ± 6.1 mL, P < 0.0001) and minimum (39.2 ± 19.1 vs. 16.0 ± 4.6 mL, P < 0.0001) volumes and LA volume before atrial contraction (53.6 ± 19.9 vs. 24.0 ± 6.2 mL, P < 0.0001) were significantly increased in HCM patients. Atrial stroke volumes respecting cardiac cycles proved to be increased, while emptying fractions were decreased in subjects with HCM. Mean global radial (-12.2 ± 6.7% vs. -19.6 ± 11.7, P < 0.05), longitudinal (26.5 ± 16.5% vs. 29.8 ± 12.1%, P < 0.05) and 3D strain (-6.1 ± 4.4% vs. -12.5 ± 10.2%, P < 0.05) proved to be significantly reduced in HCM patients as compared with matched controls. CONCLUSIONS: Three-dimensional speckle tracking echocardiography allows detailed evaluation of LA (dys) function in HCM by volumetric and strain measurements.

Three-dimensional speckle tracking echocardiography-derived left atrial strain parameters are reduced in patients with atrial fibrillation (results from the MAGYAR-path study).

OBJECTIVE: Three-dimensional (3D) speckle tracking echocardiography (3DSTE) is a novel imaging modality for assessing cardiac function. We aimed to analyze left atrial (LA) function using 3DSTE in patients with atrial fibrillation (AF). METHODS: 3DSTE was performed in 20 patients prior to their pulmonary vein isolation for AF. Every patient underwent a complete two-dimensional echocardiographic study at the same time. 3DSTE-derived circumferential (CS), longitudinal (LS), radial (RS), 3D (3DS), and area strain (AS) values were measured in the basal (b), mid (m), and superior (s) regions of the LA. 3DSTE-defined maximal (LAmax ) and minimal LA volumes (LAmin ) and LA total emptying fraction were calculated automatically. Eleven randomly selected age- and gender-matched healthy volunteers served as controls. RESULTS: Patients with AF had significantly larger LAmax and LAmin and reduced LS, RS and CS.3DS and AS were significantly lower throughout the LA in cases with AF (3DS-b, -m, -s [AF patients vs. controls]: -18 ± 8% vs. -29 ± 8%, P = 0.001; -14 ± 6% vs. -22 ± 7%, P = 0.002; -10 ± 7% vs. -20 ± 9%, P = 0.002; AS-b, -m, -s [AF patients vs. controls]: 35 ± 15% vs. 52 ± 13%, P = 0.004; 50 ± 21% vs. 72 ± 19%, P = 0.009; 31 ± 21% vs. 65 ± 27%, P < 0.0001, respectively). CONCLUSIONS: 3DSTE-derived "uni-dimensional" LS, RS, CS, as well as novel strain parameters (3DS, AS) are significantly reduced in patients with AF compared to matched controls. 3DS and AS might be new strain parameters providing further insights into the alterations of LA function in patients developing AF.

Role of triggering pulmonary veins in the maintenance of sustained paroxysmal atrial fibrillation.

BACKGROUND: Triggers from thoracic veins have been implicated not only in the initiation, but also in the perpetuation of paroxysmal atrial fibrillation (PAF). To investigate their role we studied the distribution and stability of dominant frequencies (DFs) during PAF and the response to isolation of the triggering pulmonary vein (PV). METHODS AND RESULTS: Triggering structures inducing PAF were identified during isoproterenol challenge in 26 patients (15 males, 55 ± 8.5 years). During sustained PAF, sequential recordings were made with a decapolar circular mapping catheter from each PV and the left atrial posterior wall (LAPW), together with coronary sinus (CS) and right atrium (RA) recordings. DF was determined using fast Fourier transformation. Recordings were repeated after ≥15 minutes of PAF. Radiofrequency ablation was directed first at the triggering PVs. PAF initiated from the PVs in 24 patients and from RA in two. There was a significant frequency gradient from the triggering structure to the PVs, CS, LAPW, and RA (P < 0.0001). During the second recording, DF decreased at all sites (P < 0.02), but the frequency gradient remained unchanged. Despite isolation of the triggering PV, PAF continued in 53% of patients, although DF measured in the CS was lower. AF termination occurred with contralateral PV isolation in half of the remaining patients and further AF slowing was noted in the rest. CONCLUSIONS: Triggering structures harbor the fastest activity during sustained PAF pointing to their leading role in arrhythmia perpetuation. However, nontriggering PVs also seem to contribute to PAF maintenance.

Randomized trial of intracardiac echocardiography during cavotricuspid isthmus ablation.

UNLABELLED: Randomized Trial of ICE During CTI Ablation. INTRODUCTION: Despite a high success rate, radio-frequency ablation (RFA) of the cavotricuspid isthmus (CTI) can be unusually challenging in some cases. We postulated that visualization of the CTI with intracardiac echocardiography (ICE) could maximize the success rate, decrease the procedure and ablation time, and minimize the radiation exposure. METHODS AND RESULTS: In our prospective, randomized study, we included 102 patients scheduled for CTI ablation. We randomized patients in 2 groups: guided only by fluoroscopy (n = 52) or ICE-guided (n =50) group. Procedure time, fluoroscopy time, and the time spent for RFA were significantly shorter, radiation exposure (dose-area product-DAP) and the sum of delivered radio frequency energy were significantly lower in the ICE-group (68.06 ± 15.09 minutes vs 105.94 ± 36.51 minutes, P < 0.001, 5.54 ± 3.77 minutes vs 18.63 ± 10.60 minutes, P <0.001, 482.80 ± 534.12 seconds vs 779.76 ± 620.82 seconds, P = 0.001 and 397.62 ± 380.81 cGycm(2) vs 1,312.92 ± 1,129.28 cGycm(2) , P < 0.001, 10,866.84 ± 6,930.84 Ws vs 16,393.56 ± 13,995.78 Ws, P = 0.048, respectively). Seven patients (13%) from the fluoroscopy-only group crossed over to ICE-guidance because of prolonged unsuccessful RFA and were all treated successfully. Four vascular complications and 2 recurrences were equally distributed between the 2 groups. CONCLUSIONS: ICE-guided ablation of the CTI significantly shortens the procedure and fluoroscopy time, markedly decreases radiation exposure, and time spent for ablation in comparison with fluoroscopy-only procedures. At the same time, visualization with ICE allowed successful ablation in challenging cases. (J Cardiovasc Electrophysiol, Vol. 23, pp. 996-1000, September 2012).