Natale Marrazzo

Long-Term Performance of Coronary Sinus Leads Used for Cardiac Resynchronization Therapy

Background: Little is known regarding the long‐term performance of coronary sinus (CS) leads, which have an effect on the longevity of cardiac resynchronization therapy (CRT) systems.

Appropriate therapies predict long-term mortality in primary and secondary prevention of sudden cardiac death.

Background Less than 50% of patients implanted with an implantable cardioverter-defibrillator (ICD) receive device therapy during the follow-up. The aim of our study was to prospectively evaluate the predictive role of appropriate ICD therapy on long-term survival of patients implanted for primary or secondary sudden death prevention. Methods From 2002 to 2003, 139 consecutive patients [mean age 66 ± 9 years, male 77%, ischemic heart disease 56%, New York Heart Association functional class > II (74%), primary prevention 74%, mean left ventricular ejection fraction 30 ± 9%, cardiac resynchronization ICD 65%] were enrolled. We collected and evaluated device therapies for at least 18 months and recorded survival status for more than 5 years. Results Over a median follow-up of 18 months, 54 (39%) patients received at least one ICD intervention, with 28 patients receiving only appropriate ICD therapies, 13 only inappropriate therapies and 13 receiving both therapies. At a mean follow-up of 63 ± 12 months, 30 deaths occurred in 130 patients (23%); for nine patients, we had no survival status information. Death was classified as cardiac in 22 (73%) patients, the most common cause was progressive heart failure. In a Cox proportional regression model, an appropriate ICD therapy was associated with a significant increase in the subsequent risk of death (hazard ratio 3.02, P = 0.003). Conclusion In patients implanted with ICD or cardiac resynchronization therapy with ICD devices, for primary or secondary sudden cardiac death prevention, appropriate ICD therapy predicts a three-fold greater risk of death.

Clinical and technical determinants of long-term performance of coronary sinus leads.

Objectives Little is known about coronary sinus lead performance in patients with cardiac resynchronization therapy devices. We evaluated the impact of clinical and technical parameters on coronary sinus lead performance over long-term follow-up. Methods From February 1999 to July 2004, 235 patients (181 men; mean age, 68 ± 9 years; mean left ventricular ejection fraction, 26.5 ± 6.5%; idiopathic dilated cardiomyopathy, 49%; ischemic, 48%; and other cause, 3%) underwent cardiac resynchronization therapy (pacemaker or defibrillator) implantation. Results On implantation, the only statistically significant difference was observed in mean pacing impedance, which was lower for unipolar leads than for bipolar leads (763 ± 250 vs. 847 ± 270 Ω, P = 0.02), and lower in patients with ischemic cardiomyopathy than in those with idiopathic cardiomyopathy (758 ± 204 vs. 837 ± 291 Ω, P = 0.03). After a mean follow-up of 41.7 ± 14.7 months, a significant decrease was observed in mean pacing impedance (from 811 ± 261 to 717 ± 284 Ω, P = 0.0026) and mean R-wave amplitude (from 13.2 ± 6.7 to 10.5 ± 5.5 mV, P = 0.002), whereas the mean pacing energy threshold increased from 3.6 ± 10.4 to 9.5 ± 28 μJ (P = 0.004). On analysis of variance, unipolar lead (P = 0.016) and posterior coronary sinus position (P = 0.049) were related to a greater energy threshold increase. On multivariate analysis (Cox regression), only posterior coronary sinus lead position (P = 0.013) proved to be an independent predictor of long-term significant increase in the stimulation energy threshold. Conclusion Over the long-term follow-up of coronary sinus leads, pacing impedance and R-wave amplitude decreased, whereas the energy threshold increased; unipolar leads and posterior lead location in the coronary sinus were related to a greater energy threshold increase.

Endocardial defibrillation lead extraction: An unusual case of entrapment

Spurious discharges due to late insulation break in an IS‐1 pacing/sensing connector prompted ICD lead removal in 65‐year‐old man. The tip of the lead was easily freed and pulled back into the SVC by the superior approach. After that, the lead became trapped. The distal part of the lead was caught and easily withdrawn by inferior approach. Superior venous angiography showed extravascular location of the entrapped part of the lead due to the unintentional percutaneous puncture of the innominate vein after piercing the subclavian vein. It may be desirable to use contrast venography before intervention of extraction to ensure venous patency and lead location. (PACE 2003; 26:2036–2038)

Feasibility and Safety of Two French Electrode Catheters in the Performance of Electrophysiological Studies

The aim of this study was to analyze prospectively the feasibility and safety of using 2 Fr versus 6 Fr standard electrode catheters for diagnostic electrophysiological study. Methods: Two hundred and five consecutive patients were randomized to receive the 6 Fr approach (3 quadripolar, 6 Fr, electrode catheters inserted through the left or right femoral vein and placed in the high right atrium, right ventricular apex, and His bundle area) or the 2 Fr approach (3 quadripolar, 2 Fr, electrode catheters inserted through a single, 7 Fr, triple lumen, guiding catheter and positioned at the same sites as the 6 Fr approach). Results: Introduction time was shorter in the 2 Fr group (133.3 ± 65 s, range 87–669 s) than in the 6 Fr group (242.8 ± 91.8 s, range 168–1024 s, P < 0.001). The overall fluoroscopy time was longer in the 2 Fr group (141.2 ± 40.1 s, range 78–312 s) than in the 6 Fr group (126.4 ± 39.7 s, range 58–341 s, P = 0.009). However in the last 100 patients there was no more difference between the two groups (137.6 ± 28.2 s vs 128.4 ± 23.2 s, P = 0.07). There was no significant difference between 2 Fr and 6 Fr groups in the mean atrial (5.9 ± 2.2 mV, range 2.2–11.3 mV, vs 6.1 ± 2.3 mV, range 2.4–12.4 mV, P =0.57) and ventricular (5.6 ± 2.1 mV, range 1.9–9.7 mV, vs 5.7 ± 2.2 mV, range 2.3–10.5 mV, P = 0.66) activation potential amplitudes recorded during sinus rhythm, or in the rate of stable His bundle potential recording (P = 0.3), and catheter dislodgment (P = 0.54). The overall number of complications was significantly higher in the 6 Fr group than in the 2 Fr group (29 vs 5, P = 0.001), as well as the number of entry site related complications (3 vs 12, P = 0.02) and catheter manipulation related complications (2 vs 17, P < 0.001). Conclusions: The results of this study show that the use of 2 Fr electrode catheters reduces the rates of entry site and catheter manipulation related complications during EPS. Despite their small size, these catheters allow quick and precise positioning of the electrode.