Modified serum profiles of inflammatory and vasoconstrictive factors in patients with emotional stress-induced acute coronary syndrome during World Cup Soccer 2006.

OBJECTIVES: We sought to assess whether emotional stress-induced acute coronary syndrome (ACS) is mediated by increased inflammatory and vasoconstrictive mediators. BACKGROUND: The World Cup soccer 2006 has been shown to provoke levels of stress sufficient to increase the incidence of ACS. However, the mechanisms by which stress translates into vascular injury up to plaque rupture still remain elusive. METHODS: Serum levels of soluble CD40L (sCD40L), soluble vascular cell adhesion molecule (sVCAM)-1, monocyte chemoattractant protein (MCP)-1, tumor necrosis factor (TNF)-alpha, high-sensitivity C-reactive protein (hsCRP), regulated on activation, normal T-cell expressed and secreted (RANTES), and endothelin (ET)-1 were determined in patients who experienced an ACS during World Cup matches, in ACS reference patients (not associated with emotional stress), and in healthy volunteers. Correlations and receiver-operating characteristic curves were calculated to develop multivariable analysis and to investigate the diagnostic value of each parameter. RESULTS: The sCD40L, sVCAM-1, MCP-1, TNF-alpha, and ET-1 were significantly higher in study patients compared with the reference group. The hsCRP was similar in both groups, whereas RANTES was decreased in study patients. A positive correlation was found between ET-1 and soccer-induced enhanced levels of sCD40L, sVCAM-1, MCP-1, and TNF-alpha. Receiver-operating characteristic analysis displayed high performance of both MCP-1 and ET-1 as a measure to discriminate between stress-induced ACS and ACS controls. CONCLUSIONS: Stress-induced ACS is associated with a profound increase of inflammatory and vasoconstrictive mediators. The evaluation of a targeted drug delivery, such as anti-inflammatory agents, ET-1 receptor antagonists, or inhibition of endothelin-converting enzyme is warranted to reduce stress-mediated cardiovascular morbidity.

Different forms of ventricular tachycardia involving the left anterior fascicle in nonischemic cardiomyopathy: critical sites of the reentrant circuit in low-voltage areas.

INTRODUCTION: The purpose of this study was to examine the reentrant circuit of ventricular tachycardias (VTs) involving the left anterior fascicle (LAF) in nonischemic cardiomyopathy. METHODS AND RESULTS: Six patients with nonischemic cardiomyopathy presented with VTs involving the LAF. Potentials in the diastolic or presystolic phase of the VT were identified close to the LAF in 3 patients and in the mid or inferior left ventricular (LV) septum in 3 patients. Superimposed on a CARTO or NavX 3-dimensional voltage map, the diastolic and presystolic potentials were recorded within or at the border of a low-voltage zone in the LV septum in all cases. In 2 patients, both left bundle fascicles participated in the reentrant circuit including a possible interfascicular VT in one case. Ablation targeting the diastolic or presystolic potentials near the LAF or in the midinferior LV septum eliminated the VTs in all patients with the occurrence of a left posterior fascicular block and the delayed occurrence of a complete atrioventricular block in each one patient. During the follow-up of 23 +/- 20 months after ablation, 4 patients were free of ventricular tachyarrhythmias. Due to detoriation of heart failure, one patient died after 12 months and one patient underwent heart transplantation after 40 months. CONCLUSIONS: Slow conduction in diseased myocardium close to the LAF or in the middle and inferior aspects of the LV septum may represent the diastolic pathway of VT involving the LAF.

Analysis during sinus rhythm and ventricular pacing of reentry circuit isthmus sites in right ventricular cardiomyopathy.

BACKGROUND: The entrainment mapping algorithm is used for ablation of ventricular tachycardia (VT) in right ventricular (RV) cardiomyopathy, but ablation at endocardial isthmus sites has only a moderate success rate. This study was performed to identify additional local electrogram characteristics associated with successful ablation. PATIENTS AND METHODS: Using entrainment mapping, 45 reentry circuit isthmus sites were detected in 11 patients with RV cardiomyopathy presenting with 13 monomorphic VTs. Local bipolar electrograms were retrospectively analyzed at reentry circuit isthmus sites during VT, sinus rhythm, and programmed stimulation from the right ventricular apex (RVA), and compared between successful and unsuccessful ablation sites. RESULTS: Ablation was successful at 10 reentry circuit isthmus sites and unsuccessful at 35 isthmus sites. During VT, a longer endocardial activation time relative to QRS onset, an increased electrogram-QRS interval as a percentage of VT cycle length, and a longer electrogram duration were found at successful in comparison to unsuccessful ablation sites. The presence of isolated diastolic potentials during sinus rhythm at reentry circuit isthmus sites, consistent with slow conduction or unidirectional conduction block, was associated with successful catheter ablation. Prolongation of the duration of the local multipotential electrogram by >100 ms during programmed RVA pacing at reentry circuit exit sites, indicating functional conduction disorder was also a marker of successful ablation. CONCLUSIONS: The demonstration of multipotential electrogram characteristics indicating fixed or functional conduction block may increase the likelihood of successful VT ablation at exit and central isthmus sites of reentry circuits in RV cardiomyopathy.

Outcome of ablation for sustained focal atrial tachycardia in patients with and without a history of atrial fibrillation.

OBJECTIVES: The aim of this study was to determine the long-term results of ablation for sustained focal atrial tachycardia in patients with and without a history of atrial fibrillation. METHODS: A history of atrial fibrillation was documented in 25 of 111 patients (23%) with focal atrial tachycardias. We studied the results of focal ablation during a follow-up of 27 +/- 22 months. RESULTS: Enlargement of left atrium (Odds ratio 2.99) and septal origin of the atrial focus (Odds ratio 5.68) were independent predictors of coexisting atrial fibrillation. Patients with a septal origin of the focal atrial tachycardia were older (62 vs. 54 years) and had a higher rate of structural heart disease than patients with a non-septal site of origin (51 vs. 29%). A higher rate of atrial fibrillation was found in patients with anteroseptal (56%), midseptal (50%) and posteroseptal (36%) atrial tachycardias than in patients with focal atrial tachycardias arising from the crista terminalis (9%), the tricuspid (12%) and mitral annulus (0%), the ostia of thoracic veins (17%) and other right atrial (27%) and left atrial free wall sites (10%). During the follow-up, atrial fibrillation was documented in 3% of patients without preexisting atrial fibrillation. In patients with focal atrial tachycardia and a history of atrial fibrillation, at least one episode of atrial fibrillation was documented during follow-up in 64% of patients, but 60% of patients reported marked symptomatic improvement. CONCLUSION: An increased rate of coexisting atrial fibrillation was found in patients with a septal origin of focal atrial tachycardia. Ablation of the focal atrial tachycardia may eliminate both arrhythmias, but patients with a history of atrial fibrillation may still be prone to recurrences of atrial fibrillation after focal ablation.

Different patterns of the fall of impedance as the result of heating during ostial pulmonary vein ablation: implications for power titration.

BACKGROUND: A variety of strategies have been proposed to avoid the risks of pulmonary vein ablation for atrial fibrillation. The fall of impedance during radiofrequency catheter ablation can be used as a real time measure of tissue heating. The aim of this study was to analyze the impedance fall during ostial pulmonary vein ablation and to evaluate whether adjusting power to the fall of impedance may contribute to a reduction of the risk of complications. METHODS: Analysis of biophysical parameters of ablation and determination of ostial diameters during follow-up were performed in 70 patients undergoing impedance-guided segmental ostial pulmonary vein ablation. Repeat radiographic angiography, local electrograms, and baseline impedance were the criteria to define the position of the 4-mm electrode tip at atrial sites or inside the proximal pulmonary veins. RESULTS: Energy application inside the proximal pulmonary veins led to an increased impedance fall inside the first 5-10 mm of the pulmonary veins (1.1 +/- 0.5 Omega/W) as compared to ablation at atrial sites (0.7 +/- 0.3 Omega/W) (P < 0.01). The analysis of temperature and impedance fall during ostial ablation demonstrated an increased impedance fall with heating at sites inside the proximal pulmonary veins (1.5 +/- 0.6 Omega/ degrees C) as compared to atrial sites (1.2 +/- 0.5 Omega/ degrees C) (P < 0.001). The regression lines analyzing these correlations indicated that adjusting power to a maximum impedance fall of 20 Omega would limit heating at pulmonary venous sites to lower temperatures (average maximum temperature: 48 degrees C) than at atrial sites (average maximum temperature: 63 degrees C). The ablation strategy used for segmental ostial ablation in 70 patients, which involved power limitation to a maximum impedance fall of 20 Omega, allowed isolation of 89% of targeted pulmonary veins with a low rate of impedance rises (0.3% of applications). No pulmonary vein stenoses >30% were detected by follow-up computed tomography analysis. CONCLUSIONS: An increased impedance fall as the result of heating during ostial ablation was found inside the proximal pulmonary veins as compared to atrial sites. Adjusting power to the fall of impedance during segmental ostial pulmonary vein ablation contributes to the prevention of overheating inside the pulmonary veins and may lower the risk of coagulum formation and pulmonary vein stenosis.

Transvenous defibrillation leads: high incidence of failure during long-term follow-up.

INTRODUCTION: Patients with implantable cardioverter defibrillators (ICD) critically depend on correct functioning of their system. The aim of this study was to determine the incidence and clinical presentation of transvenous ICD lead failures during long-term follow-up. METHODS AND RESULTS: The study group consisted of 261 consecutive patients who received Medtronic right ventricular polyurethane transvenous leads (models 6884, 6966, 6936) between 1990 and 1998 as part of an abdominal (n = 70) or pectoral (n = 191) ICD system. During mean follow-up of 4.0 +/- 2.6 years, 31 patients (12%) developed a lead-related sensing failure with oversensing of artifacts. All failures except two were compatible with an insulation defect and occurred late after ICD placement (6.0 +/- 1.8 years after implant). Lead survival decreased from 98% at 4-year follow-up to only 62% at 8-year follow-up. Lead survival was not related to patient age, sex, venous lead implantation route, or device implantation site. In 26 (87%) of 31 patients, a sensing defect resulted in inappropriate detection of ventricular fibrillation and subsequent delivery of 3 +/- 3 (range 1-11) inappropriate shocks in 19 (61%) of 31 patients. Device interrogation showed artifacts classified as nonsustained ventricular tachycardia in 21 patients, 40 +/- 43 days before clinically relevant failure of the system. One patient with a subclavian crush syndrome required resuscitation because of undersensing of true ventricular fibrillation. CONCLUSION: Transvenous polyurethane ICD leads showed a high rate of lead insulation failure late after implantation with frequent inappropriate shock deliveries. Close follow-up is mandatory in patients with these leads. Automated device control features with patient alert function integrated into new devices may contribute to early detection of lead failure.