Echocardiography for prediction of 6-month and late response to cardiac resynchronization therapy: implementation of stress echocardiography and comparative assessment along with widely used dyssynchrony indices.

Non-response cardiac resynchronization therapy (CRT) remains an issue, despite the refinement of selection criteria. The purpose of this study was to investigate the role of stress echocardiography along with dyssynchrony parameters for identification of CRT responders or late responders. 106 symptomatic heart failure patients were examined before, 6 months and 2-4 years after CRT implementation. Inotropic contractile reserve (ICR) and inferolateral (IL) wall viability were studied by stress echocardiography. Dyssynchrony was assessed by: (1) Septal to posterior wall motion delay (SPWMD) by m-mode. (2) Septal to lateral wall delay (SLD) by TDI. (3) Interventricular mechanical delay (IVMD) by pulsed wave Doppler for (4) difference in time to peak circumferential strain (TmaxCS) by speckle tracking. (5) Apical rocking (ApR) and septal flash (SF) by visual assessment. At 6 months there were 54 responders, with 12 additional late responders. TmaxCS had the greatest predictive value with an area under curve (AUC) of 0.835, followed by the presence of both ICR and viability of IL wall (AUC 0.799), m-mode (AUC = 0.775) and presence of either ApR or SF (AUC = 0.772). Predictive ability of ApR and of ICR is augmented if late responders are also included. Performance of dyssynchrony parameters is enhanced, in patients with both ICR and IL wall viability. Stress echocardiography and dyssynchrony parameters are simple and reliable predictors of 6-month and late CRT response. A stepwise approach with an initial assessment of ICR and viability and, if positive, further dyssynchrony analysis, could assist decision making.

Transvenous extraction of cardiac rhythm device leads: a report of the experience from a single referral centre in Greece.

INTRODUCTION: As rates of implanted cardiac electronic devices continue to rise, lead extraction procedures are crucial for the management of complications. The optimal method for such procedures has been constantly debated. We sought to review our experience of lead extraction using a conventional technique. METHODS: This was a retrospective study of lead extraction procedures in a major referral centre in Greece. Leads were extracted in a series of 66 consecutive patients (69% men, age range 53-90 years) who visited our centre between August 2008 and June 2012. The extraction procedure was performed in the catheterization lab with a widely used system composed of a locking stylet and sheath. RESULTS: A total of 120 leads were extracted (51 atrial, 69 ventricular) including 19 defibrillator leads and 9 coronary sinus leads. The most frequent indication for lead extraction was infective endocarditis (28 patients, 42%), followed by generator pocket infection (22 patients, 33%), and lead malfunction (16 patients, 24%). Extraction was achieved through the venous entry-site approach in all procedures. The leads were completely extracted in 65 patients (98.5%). Only one complication was recorded: perforation of the right atrium in one patient (1.5%), who eventually underwent emergency cardiac surgery with a good outcome. CONCLUSIONS: Our data confirm that a conventional mechanical technique is highly effective for successful extraction of all types of implanted cardiac electronic device leads and is associated with very limited complications.

Upgrading pacemaker to cardiac resynchronization therapy: an option for patients with chronic right ventricular pacing and heart failure.

INTRODUCTION: Long-term pacing from the right ventricle (RV) has been shown to induce a deleterious effect on left ventricular function. Cardiac resynchronization therapy (CRT) is an established treatment for heart failure (HF) patients. The purpose of this study was to assess the benefit from upgrading to CRT in chronically RV-paced patients with a low left ventricular ejection fraction (LVEF<35%). METHODS: Thirty-seven HF patients (age 71.4 ± 7.7, 26 male), who fulfilled CRT indications, were included. Study subjects had undergone VVI or DDD pacemaker implantation 6.1 ± 5.7 years earlier and were referred to our centre because of worsened clinical condition or a depleted battery. Patients were assessed at baseline and six months after CRT. Evaluation included NYHA classification, functional capacity assessed by six-minute walk test (6 MWT), hospitalization rate and echocardiographic assessment. RESULTS: Biventricular pacing was possible in 34 of the 37 cases (91.7%) who had their device upgraded to CRT-P (n=8) or to CRT-D (n=26). After the implementation of CRT the patients showed a noteworthy clinical improvement. Average NYHA class changed from 3.3 ± 0.6 to 2.5 ± 0.9 (p<0.001), 6 MWT performance increased from 246 ± 105 m to 321 ± 101 m (p<0.001), while six-month hospitalization rate dropped from 1.4 ± 1 to 0.7 ± 0.8 admissions (p<0.001). LVEF increased from 26.3 ± 5.4% to 31.4 ± 6.7% (p<0.001) and left ventricular end-systolic volume changed from 134.3 ± 46 mL to 111.9 ± 41.1 mL (p<0.001). A reduction in QRS duration by 28 ms (p<0.001) was also noted. CONCLUSIONS: RV-paced patients should be closely monitored, and upgrade to CRT should be considered promptly if they develop moderate or severe HF.

Bifocal right ventricular pacing: an alternative way to achieve resynchronization when left ventricular lead insertion is unsuccessful.

PURPOSE: Bifocal pacing in the right ventricle is an option for patients with end-stage heart failure in whom biventricular pacing is not possible, due to failure in left ventricular (LV) lead insertion. The purpose of this prospective study was to document the clinical response of these patients, after bifocal pacing. METHODS: From the patients referred for cardiac resynchronization therapy (CRT), from 2009 to 2010, 13 cardiac CRT candidates who underwent unsuccessful LV lead implantation were included. The bifocal system's leads were implanted in the right atrium, the right ventricular (RV) apex, and the RV outflow tract. Initial patient assessment and follow-up evaluation after 6 months included clinical criteria, echocardiographic indices, and biochemical parameters. RESULTS: From 13 patients (age 68 ± 9 years, nine male), 10 improved clinically. New York Heart Association classification was reduced by one grade (from 3.6 ± 0.5 to 2.8 ± 0.8, p < 0.005 and respectively), while hospitalizations in 6-month time were reduced from three to one (p < 0.001). Six-minute walk test (in meters) increased from 176 ± 86 to 297 ± 91 (p < 0.001) and quality of life improved (EQ-VAS scale changed from 42 ± 12.5 % to 70.8 ± 20.3 %, p < 0.001). Mean shortening in QRS duration was 31.3 ms (from 165.1 ± 16.3 to 133.8 ± 12.7, p < 0.001) and B-type natriuretic peptide (in picograms per milliliter) dropped from 834 ± 350 to 621 ± 283 (p < 0.001). Ejection fraction (in percent) increased from 27.5 ± 4.6 to 33.3 ± 4.4 (p < 0.001), and mitral regurgitation severity decreased by one grade (from 2.7 ± 0.9 to 1.8 ± 0.7, p < 0.05). CONCLUSION: RV bifocal pacing seems to offer a substantial clinical benefit to heart failure patients with traditional CRT indications and could be an alternative option when LV access is unsuccessful.

Inflammation in lone atrial fibrillation: new insights by coronary sinus thermography.

BACKGROUND: In the clinical setting there are conflicting results regarding the role of inflammatory activation in atrial fibrillation (AF). Coronary sinus (CS) thermography assesses myocardial heat production and is correlated with inflammatory states. We investigated in patients with AF whether 1) there is increased CS blood temperature and 2) the correlation of heat production with systemic inflammation. METHODS: We included patients with AF and subjects with sinus rhythm. C-reactive protein (CRP) levels were measured in all patients. CS and right atrium (RA) blood temperature measurements were performed by a dedicated 7F thermography catheter. DeltaT was calculated by subtracting RA from CS blood temperature. RESULTS: We included 47 patients with AF and 23 subjects with sinus rhythm. We stratified patients with AF into two groups: normotensive (AFN) and hypertensive (AFH). DeltaT was lower in the RA compared with the CS in AFH (37.27+/-0.52 degrees C vs 37.47+/-0.54 degrees C, p<0.01), in AFN (37.13+/-0.53 degrees C vs 37.34+/-0.54 degrees C, p<0.01), and in controls (37.41+/-0.69 degrees C vs 37.55+/-0.68 degrees C, p<0.01). DeltaTau was greater in AFH, and AFN compared to controls (0.20+/-0.07 degrees C, 0.20+/-0.08 degrees C, vs 0.14+/-0.06 degrees C, p<0.01). DeltaT was similar between AFH and AFN (p=0.95). CRP was higher in AFH and AFN compared to controls (1.72+/-0.85 mg/Dl, 1.69+/-0.94 mg/dL, 0.98+/-0.71 mg/dL, p<0.01). CRP was similar between AFH and AFN (p=0.87). A correlation between CRP with DeltaT was observed in AFH and AFN (R=0.58, p<0.01, R=0.44, p=0.02). CONCLUSIONS: Patients with AF have increased myocardial heat production, which is correlated to the systemic inflammation. CS blood temperature measurement may provide significant information for the pathogenesis of AF.

The role of the implantable loop recorder in the investigation of recurrent syncope.

Recurrent syncope is a common clinical problem. Patients with recurrent syncope frequently undergo extensive investigations that consume significant health care resources. Nevertheless, in a large percentage of patients syncope remains unexplained. The implantable loop recorder is a recognized diagnostic tool that can provide a definitive diagnosis and thus permit specific treatment. We present the case of a woman with recurrent syncope who was referred to our cardiology department for further investigation. Her last episode had led to a fall that caused her serious injuries. The initial routine workup was negative for cardiac, neurologic or metabolic causes of syncope. The implantable loop recorder revealed an arrhythmic origin for the recurrent syncope. The patient was managed appropriately with pacemaker implantation and has remained asymptomatic for one year.