The Effect of Cardiac Rehabilitation and a Specialized Clinic on Outcomes of Patients With Atrial Fibrillation.

BACKGROUND: Cardiac rehabilitation (CR) intervention programs are currently not part of management in patients with atrial fibrillation (AF). We sought to determine the effect of CR compared with a specialized AF clinic (AFC) and usual care on outcomes in patients with AF. METHODS: This was a single-centre retrospective cohort study that was carried out using 3 databases: the Hearts in Motion database (2010-2014), prospectively collected data in an AFC (2011-2014), and a retrospective chart review for patients in usual care (2009-2012). Three care pathways were compared: (1) CR; (2) AFC; and (3) usual specialist-based care. The main outcome was AF-related emergency department visits and cardiovascular hospitalizations. RESULTS: Of 566 patients with newly diagnosed AF, 133 (23.5%) patients underwent CR, 197 patients (34.8%) attended the AFC, whereas the remaining 236 (41.7%) were followed in a usual specialist-based care clinic. At 1 year, AF-related emergency department visits and cardiovascular hospitalization rates occurred in 7.5% in the CR group, 16.8% in the AFC group, and 29.2% in usual care. After a propensity matched analysis, usual care was associated with the highest rate of the main outcome (odds ratio, 4.91; 95% confidence interval, 2.09-11.53) compared with CR, as did the AFC compared with CR (odds ratio, 2.75; 95% confidence interval, 1.14-6.6). CONCLUSIONS: Among patients with AF, CR was associated with a lower risk of AF-related outcomes. These findings support further study of the use of CR in the management of these patients to determine the optimal model of care for AF patients.

Role of contact force in ischemic scar-related ventricular tachycardia ablation; optimal force required and impact of left ventricular access route.

BACKGROUND: Contact force-sensing technology has become a widely used addition to catheter ablation procedures. Neither the optimal contact force required to achieve adequate lesion formation in the ventricle, nor the impact of left ventricular access route on contact force has been fully clarified. PATIENTS AND METHODS: Consecutive patients (n = 24) with ischemic cardiomyopathy who underwent ablation for scar-related ventricular tachycardia were included in the study. All ablations (n = 25) were performed using irrigated contact force-sensing catheters (Smart Touch, Biosense Webster). Effective lesion formation was defined as electrical unexcitability post ablation at sites which were electrically excitable prior to ablation (unipolar pacing at 10 mA, 2 ms pulse width). We explored the contact force which achieved effective lesion formation and the impact of left ventricular access route (retrograde aortic or transseptal) on the contact force achieved in various segments of the left ventricle. Scar zone was defined as bipolar signal amplitude < 0.5 mV. RESULTS: Among 427 ablation points, effective lesion formation was achieved at 201 points (47.1%). Contact force did not predict effective lesion formation in the overall group. However, within the scar zone, mean contact force ≥ 10 g was significantly associated with effective lesion formation [OR 3.21 (1.43, 7.19) P = 0.005]. In the 12-segment model of the left ventricle, the retrograde approach was associated with higher median contact force in the apical anterior segment (31 vs 19 g; P = 0.045) while transseptal approach had higher median force in the basal inferior segment (25 vs 15 g; P = 0.021). In the 4-segment model, the retrograde approach had higher force in the anterior wall (28 vs 16 g; P = 0.004) while the transseptal approach had higher force in the lateral wall (21 vs 18 g; P = 0.032). There was a trend towards higher force in the inferior wall with the transseptal approach, but this was not statistically significant (20 vs 15 g; P = 0.063). CONCLUSIONS: In patients with ischemic cardiomyopathy, a mean contact force of 10 g or more within the scar zone had the best correlation with electrical unexcitability post ablation in our study. The retrograde aortic approach was associated with better contact force over the anterior wall while use of a transseptal approach had better contact force over the lateral wall.

Effect of coronary revascularization on long-term clinical outcomes in patients with ischemic cardiomyopathy and recurrent ventricular arrhythmia.

BACKGROUND: Patients with ventricular tachycardia (VT) postmyocardial infarction (MI) are a higher risk group with significant morbidity and mortality. We examined the impact of prior coronary revascularization on clinical outcomes in patients with ischemic cardiomyopathy and VT. METHODS: The VANISH trial randomized 259 patients with prior MI and antiarrhythmic drug-refractory VT to receive escalated medical therapy or catheter ablation. Clinical outcomes were compared according to whether patients have undergone prior revascularization procedures. The primary outcome was a composite of death, appropriate implantable cardiac defibrillator (ICD) shock, or VT storm. The secondary outcomes included elements of the primary outcome, hospitalization, and any ventricular arrhythmia. RESULTS: 190 patients (73%) had prior coronary revascularization. Revascularization group had more men (97% vs 83%; P  =  0.0003) and patients in that group were older (mean age 69.3 ± 7.6 vs 66.7 ± 9.2; P  =  0.04), had more renal insufficiency (22.6% vs 8.7%; P  =  0.01), and were more likely to have an implanted cardiac resynchronization device (23% vs 10%, P  =  0.03) as compared with the nonrevascularized patients. There were no significant differences in baseline medication use. There was a trend toward fewer hospitalizations in the revascularization group (64% vs 77%; P  =  0.07); there were no differences in the individual outcomes of mortality, VT storm, ICD shocks, recurrent MI, or cardiac failure. CONCLUSIONS: In this cohort of patients with an ischemic cause for VT, a history of prior coronary revascularization was not associated with a reduction in ventricular arrhythmia or mortality.

Anteroseptal basal right ventricular entrainment is simple and superior to apical entrainment in identifying mechanism of supraventricular tachycardia.

BACKGROUND: Differentiation between atrioventricular nodal reentry tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT) can be sometimes challenging. Apical right ventricular (RV) entrainment can help in differentiation; however, it has some fallacies. We thought to compare the accuracy of anteroseptal basal RV entrainment to RV apical entrainment in identifying the mechanism of supraventricular tachycardia (SVT). METHODS: Forty-two consecutive patients with SVT who underwent catheter ablation were prospectively studied. Apical RV entrainment was performed initially followed by basal entrainment from the anteroseptal basal RV avoiding His or atrial capture. Postpacing interval (PPI), PPI-tachycardia cycle length (TCL), corrected PPI-TCL, and stimulus-atrial minus ventricular-atrial (VA) intervals were measured. RESULTS: Entrainment was achieved from both sites of RV in 34 patients (ten men; mean age 42 ± 15 years), 20 with typical AVNRT, 1 with atypical AVNRT, and 13 with AVRT (eight left sided, four right sided, and one septal accessory pathways). PPI-TCL, corrected PPI (cPPI)-TCL, and stimulus-atrial-VA intervals were significantly longer with basal entrainment in AVNRT (171 ± 30 vs. 153 ± 22 ms (p = 0.003), 148 ± 21 vs. 131 ± 20 ms (p = 0.002), and 145 ± 17 vs. 136 ± 15 ms (p = 0.005), respectively). Receiver-operating characteristic curves showed higher AUC for the above parameters with basal entrainment compared to apical entrainment. Cutoff values of basal PPI-TCL of >110 ms and cPPI-TCL of >95 ms had better sensitivities (100 % for both vs. 95 and 90 %, respectively, for apical values) and specificities (85 and 92 % vs. 77 and 92 %, respectively) for diagnosis of AVNRT. CONCLUSION: Basal RV entrainment from the anteroseptal basal RV is a simple maneuver that is superior to apical ventricular entrainment in identifying the mechanism of SVT.