Considering Diastolic Dyssynchrony as a Predictor of Favorable Response in LV-Only Fusion Pacing Cardiac Resynchronization Therapy.

Background: CRT improves systolic and diastolic function, increasing cardiac output. Aim of the study: to assess the outcome of LV diastolic dyssynchrony in a population of fusion pacing CRT. Methods: Diastolic dyssynchrony was measured by offline speckle-tracking-derived TDI timing assessment of the simultaneity of E″ and A″ basal septal and lateral walls. New parameters introduced: E″ and, respectively, A″ time (E″T/A″T) as the time difference between E″ (respectively, A″) peak septal and lateral wall. Patients were divided into super-responders (SR), responders (R), and non-responders (NR). Results: Baseline characteristics: 62 pts (62 ± 11 y.o.) with idiopathic DCM, EF 27 ± 5.2%; 29% type III diastolic dysfunction (DD), 63% type II, 8% type I. Average follow-up 45 ± 19 months: LVEF 37 ± 7.9%, 34%SR, 61%R, 5%NR. The E″T decreased from 90 ± 20 ms to 25 ± 10 ms in SR with significant LV reverse remodeling (LV end-diastolic volume 193.7 ± 81 vs. 243.2 ± 82 mL at baseline, p < 0.0028) and lower LV filling pressures (E/E' 13.2 ± 4.6 vs. 11.4 ± 4.5, p = 0.0295). DD profile improved in 65% of R with a reduction in E/E' ratio (21 ± 9 vs. 14 ± 4 ms, p < 0.0001). Significant cut-off value calculated by ROC curve for LV diastolic dyssynchrony is E″T > 80 ms and A″T > 30 msec. Conclusions: The study identifies the cut-off values of diastolic dyssynchrony parameters as predictors of favorable outcomes in responders and super-responder patients with fusion CRT pacing. These findings may have important implications in patient selection and follow-up.

Factors Associated with Stroke in Atrial Fibrillation. A Retrospective Study.

AIM: The aim of our study was to retrospectively evaluate known factors such as CHA2DS2-VASc, but, also, new factors (such as left atrial remodeling), associated with the development of stroke in patients with atrial fibrillation (AFi). MATERIAL AND METHODS: We performed a retrospective study in which 251 patients with AFi were included. 47 patients had an ischemic stroke before the diagnosis of AFi, at the time of diagnosis or after AFi was diagnosed. The CHA2DS2-VASc score was analyzed for all patients together with other left atrial remodeling parameters. RESULTS: We observed that among the patients with ischemic stroke approximately 61.70% were over 72.5 years old compared to those without stroke who presented this age in a proportion of only 44.61% (OR=2.001, P=0.0367). The CHA2DS2-VASc score had the greatest statistical impact for stroke, as expected. Patients with a CHA2DS2-VASc score >4.5 presented stroke in a proportion of 87.23% compared to CHA2DS2-VASc <4.5 who had stroke only in a proportion of 12.77% (OR=11.51, P=<0.0001). Regarding left atrial remodeling parameters, low LA ejection fraction was associated with a high percentage of stroke among patients (61.70%) compared to those with LA EF>34.5% who had stroke only in a percentage of 38.30% (OR= 2.124, P=0.0238). CONCLUSIONS: Although the CHA2DS2-VASc score remains a good factor for predicting the association of AFi with ischemic stroke, echocardiographic parameters for the evaluation of the left atrium can be used as new risk factors for predicting the occurrence of ischemic stroke in patients with AFi.

A Novel and Simple Exercise Test Parameter to Assess Responsiveness to Cardiac Resynchronization Therapy.

This study assessed the value of heart rate recovery index (HRRI), a new parameter of an exercise test, as the predictor of response to cardiac resynchronization therapy (CRT). Methods: Consecutive patients receiving a CRT device were followed up after implantation and every 6 months. An effort test (ET) was quantified by minimum heart rate/maximum heart rate, as well as acceleration and deceleration times. HRRI was calculated as the ratio between acceleration and deceleration time (AT/DT) and compared to outcome. We used logistic regression to assess the predictive value of HRRI for responders and non-responders to CRT. The area under the curve (AUC) was computed to distinguish between positive and negative outcomes. Results: A total of 109 patients (74 men, mean age 63.3 ± 9.8 years) were analyzed; permanent long-term fusion CRT pacing was possible in 65 patients. Patients were assigned to two groups: responders and non-responders (98/11 patients). During a mean follow-up of 36 months, 545 ETs were performed. HRRI was significantly higher in responders versus non-responders (3.16 ± 2 vs. 1.4 ± 0.5, p < 0.001). The optimal cutoff value for HRRI as a predictor of CRT response was 1.51 (area under the receiver operating characteristic (ROC) curve = 0.844). Responders had significant left-ventricular (LV) reverse remodeling (LV end-diastolic volume = 240 ± 90 mL vs. 217 ± 89 mL, p < 0.001) and higher LV ejection fraction (26 ± 5.8% vs. 35 ± 8.7%, p < 0.001). Conclusions: HRRI computation during routine ET is useful for the evaluation of responsiveness to CRT.

Right bundle branch block and conduction disturbances in Brugada syndrome and arrhythmogenic right ventricular cardiomyopathy.

Right bundle branch block is relatively frequent in the general population and is generally considered benign in healthy individuals. However, it has been associated with increased cardiovascular risk and all-cause mortality in various cohort studies. Indeed, the presence of right bundle branch block in subjects affected by cardiomyopathies or channelopathies is not rare and may conceal underlying electrocardiographic changes, thus making the diagnosis of such conditions more challenging. The purpose of this review is to analyze the prevalence and clinical significance of right bundle branch block in subjects affected by Brugada syndrome and arrhythmogenic right ventricular cardiomyopathy.

CRT Pacing: Midterm Follow-Up in LV Only Pacing without RV Lead in Patients with Normal AV Conduction.

BACKGROUND: The aim of our study was to assess the real life cardiac resynchronization therapy (CRT) fusion left ventricular (LV) only pacing in patients with normal AV conduction (NAVc) without right ventricular (RV) lead. METHODS: Consecutive NAVc patients with CRT indication were implanted with a right atrium RA/LV DDD pacing system. Complete follow-up at 1, 3 and every 6 months thereafter included echocardiography and stress testing. RESULTS: We analysed 55 patients (62 ± 11 years). All patients were responders with significant LV reverse remodelling (LV end-diastolic volume 193.7 ± 81 vs. 243.2 ± 82 mL at baseline, p < 0.002) and increased LV ejection fraction (38 ± 7.9% vs. 27 ± 5.2% at baseline, p < 0.001). Mitral regurgitation decreased in 38 patients (69%). During follow-up (35 ± 18 months), 20 patients (36%) needed reprogramming sensed/paced AV delay or maximum tracking rate (MTR) because of inadequate or lost LV capture at exercise test; personalized programming to achieve up to 100% fusion pacing was used in all patients. One patient developed Mobitz II second degree AV block and triple chamber CRT-P upgrade was performed; defibrillator upgrade was not necessary. CONCLUSIONS: LV only pacing CRT-P without RV lead showed a positive outcome in carefully selected patients.

Diabetes mellitus and atrial remodelling in patients with paroxysmal atrial fibrillation: Role of electroanatomical mapping and catheter ablation.

Complex fractionated atrial electrograms (CFAEs) are related to atrial fibrosis, but their ablation has not yet shown superiority. The aim of the study was to compare, in terms of clinical outcome, two strategies of paroxysmal atrial fibrillation (AF) ablation in patients with type 1 diabetes mellitus (DM): pulmonary vein isolation (PVI) vs. PVI + CFAEs. Compared to an historical population of patient with paroxysmal AF and without DM, a higher percentage of patients with DM showed more than 25% of atrial area interested by CFAEs (study population, 58% vs historical group, 15%; p < 0.05). In PVI group, recurrences rate was similar in patients with HbA1c ⩽ 7.5% vs HbA1c > 7.5% (30% vs 22%; p = not significant), but a greater AF burden was observed in patients with HbA1c > 7.5% (6 ± 2 vs 1 ± 2; p < 0.05). In hazard ratios analysis PVI+CFAEs seems more effective than PVI alone in patients with HbA1c > 7.5% (hazard ratio, 1.28; p < 0.05), more than 25 years from DM diagnosis (hazard ratio, 1.25; p < 0.05) and more than five AF episodes/year (hazard ratio, 1.2; p < 0.05). Type 1 DM patients had complex atrial 'substrate', as documented by wider CFAEs areas. Despite this, 1-year follow-up recurrence rate was similar between two ablation approaches (PVI 27% vs. PVI+CFAEs 21%; p = not significant). In our study, only specific subgroups, like patients with disglycaemic state (HbA1c > 7.5%), long diabetes mellitus history and high AF burden, benefit from PVI+ CFAEs approach.