Substrate Mapping for Ventricular Tachycardia Ablation Through High-Density Whole-Chamber Double Extra Stimuli: The S3 Protocol.

BACKGROUND: A partial delineation of targets for ablation of ventricular tachycardia (VT) during a stable rhythm is likely responsible for a suboptimal success rate. The abnormal low-voltage near-field functional components may be hidden within the high-amplitude far-field signal. OBJECTIVES: The aim of this study was to evaluate the benefit and feasibility of functional substrate mapping using a full-ventricle S3 protocol and to assess its colocalization with arrhythmogenic conducting channels (CCs) on late gadolinium enhancement cardiac magnetic resonance. METHODS: An S3 mapping protocol with a drive train of S1 followed by S2 (effective refractory period + 30 ms) and S3 (effective refractory period + 50 ms) from the right ventricular apex was performed in 40 consecutive patients undergoing scar-related VT ablation. Deceleration zones (DZs) and areas of late potentials (LPs) were identified for all maps. A preprocedural noninvasive substrate assessment was done using late gadolinium enhancement cardiac magnetic resonance and postprocessing with automated CC identification. RESULTS: The S3 protocol was completed in 34 of the 40 procedures (85.0%). The S3 protocol enhanced the identification of VT isthmus on the basis of DZ (89% vs 62%; P < 0.01) and LP (93% vs 78%; P = 0.04) assessment. The percentage of CCs unmasked by DZs and LPs using S3 maps was significantly higher than the ones using S2 and S1 maps (78%, 65%, and 48% [P < 0.001] and 88%, 81%, and 68% [P < 0.01], respectively). The functional substrate identified during S3 activation mapping was significantly more extensive than the one identified using S2 and S1, including a greater number of DZs (2.94, 2.47, and 1.82, respectively; P < 0.001) and a wider area of LPs (44.1, 38.2, and 29.4 cm2, respectively; P < 0.001). After VT ablation, 77.9% of patients have been VT free during a median follow-up period of 13.6 months. CONCLUSIONS: The S3 protocol was feasible in 85% of patients, allows a better identification of targets for ablation, and might improve VT ablation results.

Aortic Regurgitation: From Valvular to Myocardial Dysfunction.

Chronic aortic regurgitation (AR) leads to volume overload in the left ventricle (LV), which is well tolerated for years. In this condition, the LV usually dilates with minimal reduction in the ejection fraction (EF), even in the absence of symptoms. Echocardiography is the primary imaging test used to quantify AR. However, no single assessment of Doppler measures is accurate and precise in individual patients; therefore, the integration of multiple parameters is necessary. Recent guidelines recommend surgical treatment for severe AR in patients who are symptomatic or have an LVEF < 55% and an end-systolic diameter > 50 mm. Nevertheless, advances in imaging technology have improved the quantification of AR and the assessment of LV subclinical dysfunction. It is widely recognized that patients who undergo aortic valve replacement/repair (AVR) due to symptoms or a low LVEF experience worse outcomes than those undergoing AVR for non-Class I indications. In fact, subclinical irreversible myocardial damage may occur in clinically well-compensated and closely monitored patients while awaiting formal surgical indications. This condition could be prevented by the use of multimodal imaging parameters, in particular longitudinal LV strain and magnetic resonance imaging. In addition, better cut-off values for mortality predictors should be established. This review aims to identify simple models that integrate several echocardiographic and cardiac magnetic resonance-derived parameters to predict the optimal timing of surgical treatment in asymptomatic patients with chronic severe AR.

Correction to: Cardiac magnetic resonance-guided limited ablation of incessant ventricular tachycardia in thrombosed left ventricle.

The original version of this article unfortunately contained a mistake. Francisco Alarcón, Susana Prat-Gonzalez, José Tomás Ortiz, Lluís Mont and Ivo Roca-Luque were not listed among the authors.

Benefits of chronic total coronary occlusion percutaneous intervention in patients with heart failure and reduced ejection fraction: insights from a cardiovascular magnetic resonance study.

BACKGROUND: Chronic total occlusion percutaneous coronary intervention (CTO-PCI) can improve angina and left ventricular ejection fraction (LVEF). These benefits were not assessed in populations with heart failure with reduced ejection fraction (HFrEF). We studied the effect of CTO-PCI on left ventricular function and clinical parameters in patients with HFrEF. METHODS: Using cardiovascular magnetic resonance (CMR), we studied 29 patients with HFrEF and evidence of viability and/or ischemia in the territory supplied by a CTO who were successfully treated with CTO-PCI. In patients with multi-vessel disease, non-CTO PCI was also performed. Imaging parameters, clinical status, and brain natriuretic peptide (BNP) levels were evaluated before and 6 months after CTO-PCI. RESULTS: A decrease in left ventricular end-systolic volume (160 ± 54 ml vs. 143 ± 58 ml; p = 0.029) and an increase in LVEF (31.3 ± 7.4 % vs. 37.7 ± 8 %; p < 0.001) were observed. There were no differences in LVEF improvement between patients who underwent non-CTO PCI (n = 11) and those without this intervention (n = 18); (p = 0.73). The number of segments showing perfusion defects was significantly reduced (0.5 ± 1 vs. 0.2 ± 0.5; p = 0.043). Angina (p = 0.002) and NYHA functional class (p = 0.004) improved, and BNP levels decreased (p = 0.004) after CTO-PCI. CONCLUSIONS: In this group of patients with HFrEF showing CMR evidence of viability and/or ischemia within the territory supplied by the CTO, an improvement in ejection fraction, left ventricular end-systolic volume and ischemia burden was observed after CTO-PCI. Clinical and laboratory parameters also improved. TRIAL REGISTRATION: ClinicalTrials.gov NCT02570087 . Registered 6 October 2015.