Anil Martin Sinha

Echocardiographic quantification of left ventricular asynchrony predicts an acute hemodynamic benefit of cardiac resynchronization therapy

OBJECTIVES We sought to determine whether radial left ventricular (LV) asynchrony in patients with heart failure predicts systolic function improvement with cardiac resynchronization therapy (CRT). BACKGROUND We quantified LV wall motion by echocardiography to correlate the effects of CRT on LV systolic function with wall motion synchrony. METHODS Thirty-four patients underwent echocardiographic phase analysis of LV septal and lateral wall motion and hemodynamic testing before CRT. Phase relationships were measured by the difference between the lateral (Phi(L)) and septal (Phi(S)) wall motion phase angles: Phi(LS) = Phi(L) - Phi(S). The absolute value of Phi(LS) was used as an order-independent measure of synchrony: the absolute value Phi(LS) = the absolute value of Phi(L) - Phi(S). RESULTS Three phase relationships were identified (mean +/- SD): type 1 (n = 4; peak positive LV pressure [dP/dt(max)] 692 +/- 310 mm Hg/s; Phi(LS) = 5 +/- 6 degrees, synchronous wall motion); type 2 (n = 17; dP/dt(max) 532 +/- 148 mm Hg/s; Phi(LS) = 77 +/- 33 degrees, delayed lateral wall motion); and type 3 (n = 13; dP/dt(max) 558 +/- 154 mm Hg/s; Phi(LS) = -115 +/- 33 degrees, delayed septal wall motion, triphasic). A large absolute value of Phi(LS) predicted a larger increase in dP/dt(max) with CRT (r = 0.74, p < 0.001). Sixteen patients were studied during right ventricular (RV), LV and biventricular (BV) pacing. Cardiac resynchronization therapy acutely reduced the absolute value of Phi(LS) from 104 +/- 41 degrees (OFF) to 86 +/- 45 degrees (RV; p = 0.14 vs. OFF), 71 +/- 50 degrees (LV; p = 0.001 vs. OFF) and 66 +/- 42 degrees (BV; p = 0.001 vs. OFF). A reduction in the absolute value of Phi(LS) predicted an improvement in dP/dt(max) in type 2 patients for LV (r = 0.87, p = 0.005) and BV CRT (r = 0.73, p = 0.04). CONCLUSIONS Echocardiographic quantification of LV asynchrony identifies patients likely to have improved systolic function with CRT. Improved synchrony is directly related to improved hemodynamic systolic function in type 2 patients.

Cardiac resynchronization therapy can reverse abnormal myocardial strain distribution in patients with heart failure and left bundle branch block.

OBJECTIVES We studied the effects of cardiac resynchronization therapy (CRT) on regional myocardial strain distribution, as determined by echocardiographic strain rate (SR) imaging. BACKGROUND Dilated hearts with left bundle branch block (LBBB) have an abnormal redistribution of myocardial fiber strain. The effects of CRT on such abnormal strain patterns are unknown. METHODS We studied 18 patients (12 males and 6 females; mean age 65 +/- 11 years [range 33 to 76 years]) with symptomatic systolic heart failure and LBBB. Doppler myocardial imaging studies were performed to acquire regional longitudinal systolic velocity (cm/s), systolic SR (s(-1)), and systolic strain (%) data from the basal and mid-segments of the septum and lateral wall before and after CRT. By convention, negative SR and strain values indicate longitudinal shortening. RESULTS Before CRT, mid-septal peak SR and peak strain were lower than in the mid-lateral wall (peak SR: -0.79 +/- 0.5 [septum] vs. -1.35 +/- 0.8 [lateral wall], p < 0.05; peak strain: -7 +/- 5 [septum] vs. -11 +/- 5 [lateral wall], p < 0.05). This relationship was reversed during CRT (peak SR: -1.35 +/- 0.8 [septum] vs. -0.93 +/- 0.6 [lateral wall], p < 0.05; peak strain: -11 +/- 6 [septum] vs. -7 +/- 6 [lateral wall], p < 0.05). Cardiac resynchronization therapy reversed the septal-lateral difference in mid-segmental peak strain from -46 +/- 94 ms (LBBB) to 17 +/- 92 ms (CRT; p < 0.05). CONCLUSIONS Left bundle branch block can lead to a significant redistribution of abnormal myocardial fiber strains. These abnormal changes in the extent and timing of septal-lateral strain relationships can be reversed by CRT. The noninvasive identification of specific abnormal but reversible strain patterns should help to improve patient selection for CRT.

Cardiac resynchronization therapyhomogenizes myocardial glucosemetabolism and perfusion in dilatedcardiomyopathy and left bundle branch block

Abstract Objectives We investigated whether cardiac resynchronization therapy (CRT) affects myocardial glucose metabolism and perfusion in dilated cardiomyopathy (DCM) and left bundle branch block (LBBB). Background Patients with DCM and LBBB present with asynchronous left ventricular (LV) activation, leading to reduced septal glucose metabolism. Cardiac resynchronization therapy recoordinates LV activation, but its effects on myocardial glucose metabolism and perfusion remain unknown. Methods In 15 patients (10 females; 61 ± 13 years) with DCM and LBBB (QRS width 165 ± 15 ms), gated 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET) and technetium-99m ( 99m Tc)-sestamibi single-photon emission computed tomography were performed before and after two weeks of CRT. Uptake of FDG and 99m Tc-sestamibi was determined in four LV wall areas. Ejection fraction and volumes were calculated from gated PET. Results Baseline FDG uptake was heterogeneous (p 99m Tc-sestamibi uptake was modest (lowest septal 65 ± 10%; maximum lateral 84 ± 5%) and also reduced with CRT, although some heterogeneity (p 99m Tc-sestamibi uptake (0.77 ± 0.13 to 0.85 ± 0.16, p Conclusions Glucose metabolism is reduced more than perfusion in the septal compared with LV lateral wall in patients with DCM and LBBB. Cardiac resynchronization therapy restores homogeneous myocardial glucose metabolism with less influence on perfusion.

Multislice spiral computed tomography for the detection of coronary stent restenosis and patency

BACKGROUND Multislice spiral computed tomography (MSCT) has evolved as a new promising method for non-invasive visualization of the coronary arteries and detection of native coronary artery stenosis. We determined the value of MSCT to non-invasively detect significant in-stent restenosis after coronary artery stenting. METHODS Twenty patients (age 56.3+/-8.6 years) were investigated by MSCT (4x1 mm cross-sections, 500 ms tube rotation, table feed 1.5 mm/rotation, intravenous contrast agent, retrospectively ECG-gated image reconstruction) at a mean interval of 9.6+/-4.2 months after coronary stent implantation. Results were compared with conventional quantitative coronary angiography (QCA). A total number of 32 stents were studied, four different stent types were evaluated. RESULTS QCA showed in-stent restenosis >50% diameter stenosis in five (16%) stents. Using MSCT it was impossible in all stents, irrespective of stent type or diameter, to directly visualize the stent lumen due to partial volume effects and beam hardening. MSCT allowed the visualization of the coronary vessel proximal and distal to the stent. This allowed confirmation of stent patency in 18/18 cases and correct identification of total stent occlusion in two patients. CONCLUSIONS MSCT allows no direct visualization of coronary in-stent restenosis, but it correctly differentiates between stent patency and stent occlusion. The reasons are mainly partial volume effects and beam hardening, which are induced by the stent material.

Cryptogenic Stroke and underlying Atrial Fibrillation (CRYSTAL AF): design and rationale.

BACKGROUND Patients with atrial fibrillation (AF) are at increased risk for ischemic stroke. In patients who have suffered a stroke, screening for AF is routinely performed only for a short period after the stroke as part of the evaluation for possible causes. If AF is detected after an ischemic stroke, oral anticoagulation therapy is recommended for secondary stroke prevention. In 25% to 30% of stroke patients, the stroke mechanism cannot be determined (cryptogenic stroke). The incidence of paroxysmal AF undetected by short-term monitoring in patients with cryptogenic stroke is unknown, but has important therapeutic implications on patient care. The optimum monitoring duration and method of AF detection after stroke are unknown. The purpose of this study is to evaluate the incidence of AF and time to AF detection in patients with cryptogenic stroke using an insertable cardiac monitor. STUDY DESIGN The CRYSTAL AF trial is a randomized prospective study to evaluate a novel approach to long-term monitoring for AF detection in patients with cryptogenic stroke. Four hundred fifty cryptogenic stroke patients (by definition, without a history of AF) will be enrolled at approximately 50 sites in Europe, Canada, and the United States. Patients will be randomized in a 1:1 fashion to standard arrhythmia monitoring (control arm) or implantation of the subcutaneous cardiac monitor (Reveal XT; Medtronic, Inc, Minneapolis, MN) (continuous monitoring arm). OUTCOMES The primary end point is time to detection of AF within 6 months after stroke. The clinical follow-up period will be at least 12 months. Study completion is expected at the end of 2012.

Incidence of oesophageal wall injury post-pulmonary vein antrum isolation for treatment of patients with atrial fibrillation

AIMS Oesophageal injury has been reported with delivery of radio-frequency lesions at the left atrium posterior wall in catheter ablation procedures for atrial fibrillation (AF). In this observational study we prospectively assessed endoscopical oesophageal wall changes after pulmonary vein antrum isolation (PVAI) in patients presenting for treatment of AF. METHODS AND RESULTS Twenty eight patients (18 men; mean age 55 +/- 11 years) were ablated using either a cooled-tip or an 8 mm tip ablation catheter. Endoscopy of the oesophagus was performed 24 h after PVAI. If oesophageal wall changes were detected post ablation, a proton-pump inhibitor (PPI) was started and repeat endoscopy was considered. Within 24 h post ablation oesophageal wall changes were confirmed in 47% of our study patients. Erythema was identified in 29% and necrotic or ulcer-like changes in 18% of patients. None of study patients experienced left atrial-oesophageal fistula. A significant correlation between Reflux-like symptoms and oesophageal wall changes was demonstrated. Complete recovery of oesophageal lesions was shown in all study patients 2-4 weeks post ablation. CONCLUSION A significant number of patients experienced oesophageal wall injury post PVAI. Initiating PPIs in this group of patients might facilitate recovery of oesophageal wall injuries caused by radio-frequency energy delivery.

Prospective randomised trial evaluating a paclitaxel-coated balloon in patients treated with endothelial progenitor cell capturing stents for de novo coronary artery disease

Background Percutaneous coronary intervention with stent implantation is limited by the occurrence of re-stenosis and the risk of stent thromboses. Objective To define the impact of paclitaxel-coated balloon angioplasty plus endothelial progenitor cell capturing (EPC) stent implantation in de novo coronary artery disease. This combination may reduce neointimal proliferation within the EPC stent and address the risk of stent thrombosis by facilitating rapid endothelialisation. Methods In this prospective single-blind multicentre randomised trial, 120 patients with a de novo lesion in a native coronary artery were randomly assigned to undergo treatment with paclitaxel-coated balloon plus EPC stent or EPC stent alone. Dual antiplatelet therapy was prescribed for 3 months. Angiographic follow-up was scheduled at 6 months. The primary endpoint was in-stent late lumen loss. The secondary clinical endpoint was a composite of death from a cardiac cause, myocardial infarction attributed to the target vessel or target lesion revascularisation. Results There was no difference in patient baseline characteristics or procedural results. The angiographic follow-up rate was 96%. Treatment with paclitaxel-coated balloon plus EPC stent was superior to EPC stent alone, with an in-stent late loss of 0.34±0.45 mm versus 0.88±0.48 mm (p<0.001). The re-stenosis rate was reduced from 23.2% to 5.1% (p=0.006) and the clinical endpoint was reduced from 17.2% to 4.8% (p=0.039). There was no definite or probable stent thrombosis. Conclusions Paclitaxel-coated balloon plus EPC stent implantation is superior to EPC stent implantation alone for treatment of de novo coronary artery disease. Trial registration NCT00732953.

Three-dimensional left atrial and esophagus reconstruction using cardiac C-arm computed tomography with image integration into fluoroscopic views for ablation of atrial fibrillation: Accuracy of a novel modality in comparison with multislice computed tomography

BACKGROUND Visualization of the left atrium (LA) and pulmonary veins (PVs) is crucial in PV isolation (PVI). Additional delineation of the esophagus might avoid severe side effects. Cardiac C-arm computed tomography (DynaCT Cardiac, Siemens AG, Forchheim, Germany) has been introduced as a novel intraprocedural imaging modality based on a rotational angiography. OBJECTIVES The purpose of this study was to prove the quantitative accuracy of DynaCT Cardiac as compared with multislice CT (MSCT) in imaging of the LA and PV in patients undergoing PVI. METHODS Thirty-four consecutive patients (22 male, age 64 +/- 12 years) with symptomatic atrial fibrillation (AF) and indication for PVI were studied. Diameters of the PV, the LA appendage (LAA), and the descending aorta were measured, and the position of the esophagus was defined using preprocedural MSCT and intraprocedural DynaCT Cardiac. RESULTS There was a significant correlation between both measurements for diameters of the LAA (r = 0.86, P <.05), PV (r = 0.98, P <.05), and the descending aorta (r = 0.98, P <.05). The overall correlation of vessel diameters was r = 0.99. The LA volumes correlation was r = 0.86 and P <.05. A significant difference of the esophageal position was found between preprocedural MSCT and intraprocedural DynaCT Cardiac (r = 0.53, P <.05). CONCLUSIONS DynaCT Cardiac is a novel intraprocedural rotational angiographic technique. It is highly accurate in displaying crucial structures for PVI in comparison with the results of MSCT. Therefore, DynaCT Cardiac can be used as an alternative imaging technique to improve PVI accuracy.

Impact of sleep‐related breathing disorders on health‐related quality of life in patients with chronic heart failure

Quality of life in patients with chronic heart failure (HF) is often severely compromised. Sleep‐related breathing disorders (SRBD) like Cheyne–Stokes Respiration (CSR) or obstructive sleep apnea (OSAS) are often observed in patients with severe HF resulting in fragmentation of sleep, excessive daytime sleepiness and an increased mortality. While an apnea/hypopnea‐index (AHI) >30/h represents an independent predictor of poor prognosis, clinical relevance of even minor SRBD with an AHI <30/h remains unclear with respect to quality of life, exercise capacity or depression rate.

Role of left ventricular scar and Purkinje-like potentials during mapping and ablation of ventricular fibrillation in dilated cardiomyopathy.

Background: Purkinje‐like potentials (PLPs) have been described as important contributors to initiation of ventricular fibrillation (VF) in patients with normal hearts, ischemic cardiomyopathy, and early after‐myocardial infarction.