Endre Zima

Stabilization of the coronary sinus electrode position with coronary stent implantation to prevent and treat dislocation.

Introduction: Coronary sinus (CS) leads used for cardiac resynchronization have undergone development in the last years. However, dislocation rate remained high (5–9%). The aim of this study was to investigate the effectiveness and safety of stent implantation in a CS side vein to stabilize the left ventricular lead position after postoperative or intraoperative dislocation of the electrode.

Gold-Tip Electrodes—A New “Deep Lesion” Technology for Catheter Ablation? In Vitro Comparison of a Gold Alloy Versus Platinum–Iridium Tip Electrode Ablation Catheter

Radiofrequency (RF) catheter ablation is widely used to induce focal myocardial necrosis using the effect of resistive heating through high‐frequency current delivery. It is current standard to limit the target tissue–electrode interface temperature to a maximum of 60–70°C to avoid char formation. Gold (Au) exhibits a thermal conductivity of nearly four times greater than platinum (Pt–Ir) (3.17 W/cm Kelvin vs 0.716 W/cm Kelvin), it was therefore hypothesized that RF ablation using a gold electrode would create broader and deeper lesions as a result of a better heat conduction from the tissue–electrode interface and additional cooling of the gold electrode by “heat loss” to the intracardiac blood. Both mechanisms would allow applying more RF power to the tissue before the electrode–tissue interface temperature limit is reached. To test this hypothesis, we performed in vitro isolated liver and pig heart investigations comparing lesion depths of a new Au‐alloy‐tip electrode to standard Pt–Ir electrode material.

Effect of cardiac resynchronization therapy with implantable cardioverter defibrillator versus cardiac resynchronization therapy with pacemaker on mortality in heart failure patients : results of a high-volume, single-centre experience

There are limited and contradictory data on the effects of CRT with implantable cardioverter defibrillator (CRT‐D) on mortality as compared with CRT with pacemaker (CRT‐P).

Long-term experience with coronary sinus side branch stenting to stabilize left ventricular electrode position

BACKGROUND Despite technical advancements, implantation of coronary sinus (CS) leads may be challenging, and dislocation remains a relevant clinical problem. OBJECTIVE The aim of this study was to investigate the effectiveness, safety, and long-term outcome of stent implantation to anchor the lead to the wall of the CS side branch. METHODS Stenting of a CS side branch was performed in 312 patients. The procedure was performed because of postoperative lead dislocation in 16 patients and because of an intraoperative unstable lead position or phrenic nerve stimulation in 296 cases. A bare metal coronary stent was introduced over a second guide wire in the same CS sheath. The stent was deposited 5-35 mm proximal to the most proximal electrode. Mechanical damage of the CS side branch or pericardial effusion was not observed owing to stenting. RESULTS During follow-up (median 28.4, interquartile range 15-37, maximum 70 months), a clinically important increase in the left ventricular pacing threshold was found in four cases and reoperation was necessary in only two patients (0.6%). Phrenic nerve stimulation was observed in 18 instances, and repositioning with an ablation catheter was performed in seven cases. Impedance measurements did not suggest lead insulation failure. Three stented leads were extracted without complication after 3-49 months owing to infection, while four leads were extracted easily during heart transplantation after 7-27 months. CONCLUSION Stent implantation to stabilize CS lead position seems to be an effective and safe procedure in prevention and treatment of CS lead dislocation in selected cases.

Minimal invasive coronary sinus lead reposition technique for the treatment of phrenic nerve stimulation

AIMS Phrenic nerve stimulation (PNS), which is often intolerable for the patient, is a known complication of resynchronization therapy. We describe a new, minimal invasive method for treating PNS. METHODS AND RESULTS Untreatable PNS was found in nine cardiac resynchronization therapy patients with distal coronary sinus (CS) lead position 6 +/- 6 (0.5-17) months after the implantation. Ablation catheter and Amplatz Left 2 type guiding catheter were introduced into the right atrium via the right femoral vein. Coronary sinus was cannulated with the Amplatz catheter, and on a normal guide wire, a coronary stent was introduced beside the lead into the side branch in seven cases or a bigger stent into the CS in two patients. The ablation catheter was looped around the CS lead in the atrium with bent tip and was drawn backward together with the CS electrode. New lead positions were evaluated with electrophysiological measurements, and the suitable position was stabilized with inflation of the stent. Pericardial effusion was not detected on post-operative echocardiography. After repositioning, suitable pacing parameters were registered (threshold: 1.6 +/- 1.1 V; 0.5 ms, impedance: 565 +/- 62 ohm). Phrenic nerve stimulation was not found with 7.5 V; 1.5 ms pacing. During follow-up (7.7 +/- 4.6 months), stable pacing threshold and impedance values were measured; transient and reprogrammable PNS was present in only one patient. CONCLUSION Coronary sinus electrode reposition using the femoral approach seems to be a safe and effective procedure, which means smaller burden for the patients compared with the established reposition operation. The technique can be used successfully if the CS lead is in a distal position.

The role of levosimendan in acute heart failure complicating acute coronary syndrome: A review and expert consensus opinion

Acute heart failure and/or cardiogenic shock are frequently triggered by ischemic coronary events. Yet, there is a paucity of randomized data on the management of patients with heart failure complicating acute coronary syndrome, as acute coronary syndrome and cardiogenic shock have frequently been defined as exclusion criteria in trials and registries. As a consequence, guideline recommendations are mostly driven by observational studies, even though these patients have a particularly poor prognosis compared to heart failure patients without signs of coronary artery disease. In acute heart failure, and especially in cardiogenic shock related to ischemic conditions, vasopressors and inotropes are used. However, both pathophysiological considerations and available clinical data suggest that these treatments may have disadvantageous effects. The inodilator levosimendan offers potential benefits due to a range of distinct effects including positive inotropy, restoration of ventriculo-arterial coupling, increases in tissue perfusion, and anti-stunning and anti-inflammatory effects. In clinical trials levosimendan improves symptoms, cardiac function, hemodynamics, and end-organ function. Adverse effects are generally less common than with other inotropic and vasoactive therapies, with the notable exception of hypotension. The decision to use levosimendan, in terms of timing and dosing, is influenced by the presence of pulmonary congestion, and blood pressure measurements. Levosimendan should be preferred over adrenergic inotropes as a first line therapy for all ACS-AHF patients who are under beta-blockade and/or when urinary output is insufficient after diuretics. Levosimendan can be used alone or in combination with other inotropic or vasopressor agents, but requires monitoring due to the risk of hypotension.

The Effect of Induction Method on Defibrillation Threshold and Ventricular Fibrillation Cycle Length

Introduction: Since no clinical data are available on the comparison of the “shock on T‐wave” and “high frequency burst” ventricular fibrillation (VF) induction modes during defibrillation threshold (DFT) testing, we aimed to compare these two methods during implantable cardioverter defibrillator implantation.

Usefulness of electroanatomical mapping during transseptal endocardial left ventricular lead implantation

AIM Failure rate to implant left ventricular (LV) lead transvenously is 4-8% in cardiac resynchronization therapy (CRT) patients. Epicardial lead placement is an alternative method and if not applicable case reports and small series showed the feasibility of endocardial LV lead implantation. Electroanatomical mapping might be a useful tool to guide this procedure. METHODS AND RESULTS Four patients had undergone endocardial LV lead implantation after unsuccessful transvenous implantation or epicardial LV lead dysfunction using the transseptal approach. Electroanatomical mapping was used to mark the location of the transseptal puncture. This location point guided the mapping catheter from the subclavian access and facilitated positioning of the LV lead at the adjacent latest activation area of the left ventricle detected by activation mapping. Endocardial active fixation LV leads were successfully implanted in all patients with stable electrical parameters immediately after implantation and over a mean follow-up of 18.3 months (lead impedance 520 ± 177 vs. 439 ± 119 Ω and pacing threshold 0.8 ± 0.2 V, 0.5 ms vs. 0.6 ± 0.1 V, 0.5 ms, respectively). Patients were maintained on anticoagulation therapy with a target international normalized ratio of 3.5-4.5 and did not show any thromboembolic, haemorrhagic events, or infection. Echocardiography showed significant improvement of LV systolic function with marked improvement of the functional status. CONCLUSIONS Electroanatomical mapping is a useful technical tool to guide endocardial LV lead implantation. It helps to identify the location of the transseptal puncture and the use of activation mapping might facilitate location of the optimal lead positions during CRT.

Shortening the Second Phase Duration of Biphasic Shocks: Effects of Class III Antiarrhythmic Drugs on Defibrillation Efficacy in Humans

Optimizing the Second Phase of Biphasic Shocks. Introduction: The specific waveform providing optimal defibrillation threshold (DFT) is unknown. We compared the defibrillation efficacy of biphasic pulses with second phases (P2) of 2 and 5 msec in a randomized prospective clinical study.

Plasma nociceptin/orphanin FQ levels are lower in patients with chronic ischemic cardiovascular diseases--A pilot study.

BACKGROUND Clinical studies are limited regarding the role of human nociceptin/orphanin FQ (N/OFQ) in ischemic cardiovascular diseases, which are still the number one cause of death in the developed world. The aim of our study was to measure the plasma levels of N/OFQ in patients with chronic ischemic cardiovascular diseases in a pilot study. METHODS AND RESULTS Our study population consisted of 22 patients presenting symptoms of stable angina pectoris (SAP): 12 severe Canadian Cardiovascular Society (CCS) III-IV functional class, and 10 with milder SAP (CCS II-III). 12 patients were also enrolled with chronic peripheral artery disease (9 with intermittent claudication; 3 with rest pain and gangrene). Patients were asked to avoid any exertion or given analgetics for their rest pain. Patients had no episodes of chest or limb pain in 1week before their fasting blood samples were taken and N/OFQ plasma levels were measured by radioimmunoassay. 14 healthy subjects without any cardiac risk factors served as a control group. CONCLUSIONS N/OFQ levels were significantly lower in patient groups with severe vs. milder chronic angina (p<0.05) and vs. control subjects (p<0.01). Patients suffering from peripheral artery disease had also a lower plasma N/OFQ levels than in healthy controls (p<0.01). Our findings show that chronic ischemic conditions of atherosclerotic origin are associated with significantly lower plasma N/OFQ levels.