Prolonged burst as a new method for cardioverter-defibrillator testing.

AIM: To find out whether it is possible to anaesthetize patients safely without analgesia and sedation, using burst pacing prolonged until the patient becomes unconscious. METHODS: One hundred and four patients undergoing implantation or reimplantation of a cardioverter-defibrillator were included. Patients randomized into Group B underwent prolonged burst pacing without analgesia and sedation. Patients in Group T underwent a T-wave shock under analgesia and sedation. Blood samples for measurement of serum neuron-specific enolase were taken before surgery and 6, 24, and 48 h after the procedure. RESULTS: From the 104 patients, 51 were randomly assigned to Group B and 53 to Group T. Four patients from Group B were switched to Group T (ventricular fibrillation not induced by burst pacing). The clinical characteristics of both groups were similar. The mean total time of cardiac arrest was significantly longer in Group B (23.0 ± 4.4 s, median 22.7) vs. Group T (10.3 ± 3.0 s, median 10.0), P < 0.0001 (Mann-Whitney U-test). The effectiveness of both induction methods was similar (92.1% in Group B and 100% in Group T). The mean neuron-specific enolase levels after 6, 24, and 48 h were similar in Groups B and T (13.1 ± 6.3 and 11.6 ± 5.8 mg/L, 14.5 ± 7.5 and 13.4 ± 6.0 mg/L, and 14.9 ± 5.9 and 12.2 ± 6.0 mg/L, respectively) as were these levels compared with baseline neuron-specificenolase levels (14.0 ± 5.9 and 13.4 ± 4.0 mg/L, respectively), P = NS for all. CONCLUSION: Despite a longer time of total cardiac arrest, prolonged burst pacing appears to be a safe and effective method for induction of ventricular fibrillation during cardioverter-defibrillator testing, which enables omission of analgesia and sedation or general anaesthesia.

Prediction of long-term reverse left ventricular remodeling after revascularization or medical treatment in patients with ischemic cardiomyopathy: a comparative study between SPECT and MRI.

Patients with ischemic heart disease and depressed left ventricular (LV) ejection fraction (LVEF) develop varying degrees of LV remodeling after cardiac surgical revascularization. Fifty-three patients with stable ischemic heart disease and impaired LV function (LVEF 34.9 ± 4%) were prospectively followed up for 24 months. Thirty-seven patients underwent coronary artery bypass grafting (CABG), 16 patients were treated conservatively. Cardiac magnetic resonance imaging (MRI) and SPECT were performed at baseline and after 12 and 24 months of follow-up. The patients were divided into responders and non-responders depending on the degree of LVEF improvement at 24 months follow-up (>5%-responders). MRI with ≤5 segments with DE/wall thickness ratio (DEWTR) ≥50% predicted LV reverse remodeling with a sensitivity of 86% and a specificity of 75% (AUC 0.81). An MRI finding of ≤2 segments with the DEWTR ≥75% had a corresponding sensitivity of 71% and specificity of 67% (AUC 0.75) while fixed perfusion defect on SPECT <16.5% of LV predicted reverse remodeling with a sensitivity of 64% and a specificity of 69% (AUC 0.64). A preoperative number of segments with the DE/wall thickness ratio of ≥50 and ≥75% obtained by MRI, was found to be a better predictor of left ventricular reverse remodeling than fixed perfusion defect by SPECT. No other MRI or SPECT parameter predicted LVEF improvement at 24 months after CABG.

Individual differences in the effectiveness of intracoronary bone marrow cell transplantation assessed by gated sestamibi SPECT/FDG PET imaging.

BACKGROUND: The impact of different levels of tracer uptake on improvements of left-ventricular (LV) function was analyzed in patients treated by intracoronary bone marrow cell (BMC) transplantation. METHODS AND RESULTS: Thirty-one patients with irreversible damage after their first acute myocardial infarction (MI), as confirmed by sestamibi single-photon emission computed tomography (MIBI SPECT)/fluorodeoxyglucose positron emission tomography (FDG PET), underwent high-dose (1 x 10(8) cells) BMC transplantation, whereas 31 similar patients were randomly integrated into a control group. In 11 BMC-treated patients with very low sestamibi uptake at less than 30% of maximum in the infarcted area, the mean left-ventricular ejection fraction (LVEF) improved after 3 months of follow-up by 3% only, and mean end-diastolic/end-systolic volumes (EDV/ESV) enlarged by 10/1 mL (P = NS vs controls). In 20 BMC-treated patients with higher sestamibi uptake in the range of 31% to 50% of maximum, LVEF improved by 7%, and EDV/ESV decreased by 5/12 mL (P < .05 vs BMC-treated subgroup with low MIBI uptake and controls). No similar categorization was seen in the control group: in patients with higher sestamibi uptake or very low uptake, the LVEF increased by 2% and 3% only, and the EDV/ESV enlarged in both subgroups by 12/4 mL and 12/2 mL, respectively (P = NS). CONCLUSIONS: Our results suggest the capability of SPECT/PET imaging to select patients who will receive the maximum benefit from BMC therapy.

Case report: Symptoms of advanced heart failure--a case for radiofrequency catheter ablation?

A sixty-year-old man with previous history of coronary artery disease was admitted due to progressive worsening of dyspnoea at exertion (NYHA III functional class) and no angina. Coronary angiography confirmed occlusion of the right coronary artery which was naturally bypassed by homocollaterals with TIMI 3 flow to the peripheral branches. The lesion was not technically suitable for percutaneous angioplasty. The left coronary artery was without stenosis. On echocardiography, both the left ventricle and the left atrium were dilated and hemodynamically significant mitral regurgitation was present. Surface ECG showed a left bundle branch block with repeated runs of monomorphic ventricular ectopic beats (PVC). Radiofrequency catheter ablation of the focus in the posteroseptal region of the left ventricle underneath the mitral valve was performed using electroanatomical mapping system. After the procedure, mitral regurgitation decreased and reverse remodeling of the left ventricle and the left atrium occurred with concomitant significant clinical improvement of the patient. The authors discuss several treatment strategies: mitral valve repair surgery combined with revascularization, implantation of a biventricular ICD system or elimination of the focus of monomorphic VT runs by radiofrequency catheter ablation as a possible causal approach in the treatment of PVC-induced cardiomyopathy.

Short-term spectral analysis of heart rate variability during supine-standing-supine test in patients with paroxysmal atrial fibrillation.

The aim of the study was to assess the sympathovagal balance in group of 27 patients without significant structural heart disease after an attack of atrial fibrillation. The investigation was performed using spectral analysis of heart rate variability during examination under conditions of different orthostatic loads in single phases, called the supine-standing- supine test. The findings were compared with a group of healthy persons. These revealed a significantly decreased total spectral power (430.7 vs 1558.0 ms(2) supine1; 477.6 vs 1042,5 ms(2) standing; 567.5 vs 1948.5 ms(2) supine2), and spectral power of the high frequency spectral component (140.8 vs 619.3 ms(2) supine1; 96.2 vs 203.3 ms(2) standing; 186.3 vs 739.4 ms(2) supine2) in the studied group of patients in comparison with the control group.

Monocyte chemoattractant protein-1 in patients with peripheral arterial disease.

BACKGROUND: Chemokine-driven migration of inflammatory cells has been implicated in the pathogenesis of atherosclerotic conditions including peripheral arterial disease (PAD). Monocyte chemoattractant protein-1 (MCP-1) is elevated in patients with coronary artery disease and in hypertensive patients. This study therefore investigated MCP-1 in patients with PAD. METHODS: Serum MCP-1 was determined by enzyme-linked immunosorbent assay in 36 healthy, control subjects and in 19 patients with PAD. Statistical analysis utilised the Mann-Whitney test and Spearman correlation (p < 0.05). RESULTS: MCP-1 (pg/ml) was increased in patients compared with in controls (mean+/-standard error of the mean: PAD group, 748+/-60; control group, 459+/-27; p=0.0001). MCP-1 levels tended to decrease with progressing disease. From atherosclerosis risk factors, diabetes inclined to increase MCP-1 levels; hypertension had no effect. Serum MCP-1 correlated with cholesterol, triglycerides, low-density lipoprotein but not high-density lipoprotein. CONCLUSION: Elevation of MCP-1 in the circulation of PAD patients shown in the present pilot study implicates this CC chemokine ligand 2 in inflammatory processes contributing to PAD clinical symptomatology. Further investigations are necessary to evaluate whether MCP-1 can be used as a potential marker of peripheral arterial disease follow-up and/or prognosis.

Triple-site pacing in patients with biventricular device-incidence of the phenomenon and cardiac resynchronization benefit.

BACKGROUND: In patients with biventricular pacing (BIV), triple-site pacing (TSP), i.e. standard biventricular cathodal pacing of the right and the left ventricle plus additional anodal capture of the right ventricle, is sometimes present. AIMS: To evaluate the incidence of TSP phenomenon, to examine TSP-related QRS changes, and to assess the effect of TSP on intraventricular resynchronization by means of tissue Doppler imaging (TDI). METHODS AND RESULTS: 23 patients with a first generation biventricular device (Medtronic 8040) and 16 patients with a new generation device (Medtronic 8042) were evaluated to look for the presence of TSP. TSP was found in 6 patients (26%) with the Medtronic 8040 (group I) and in 13 patients (81%) with the Medtronic 8042 device (group II). QRS duration decreased by 10 to 20 ms and QRS amplitude of leads I and aVL increased in almost all patients in group I during TSP modality. In group II, QRS morphology, duration and amplitude did not change as obviously. TDI analysis of the left ventricular (LV) basal segments showed significant shortening of the systole, together with a corresponding prolongation of the diastole, at the inferior wall of the LV, during TSP compared to standard BIV in all patients ( p < 0.01). Other LV segments did not show any change. Qualitative TDI electro-mechanical activation pattern of all LV segments improved in 22%, while it remained unchanged in 72%. CONCLUSIONS: TSP phenomenon can be identified in approximately a quarter of patients with the first-generation biventricular devices on the basis of the QRS morphology changes. In the second-generation biventricular pacemakers it can be demonstrated in the vast majority of patients. TSP may increase the effectiveness of cardiac resynchronization therapy by counteracting the regional activation delay located at the inferior wall of the LV.

Assessment of spectral analysis of heart rate variability in patients with history of atrial fibrillation by means of age-dependent parameters.

Heart rate variability evaluation is a useful diagnostic tool for autonomic nervous balance assessment. The role of the autonomic nervous system in aetiology of atrial fibrillation is sometimes clear as a trigger from a patient's history, but mostly it acts as a modulating factor which is not easy to detect. The present study demonstrates results of spectral analysis of short-term heart rate variability during ortho-clinostatic tests processed by means of age-dependent parameters. An original telemetric system and a unique method for heart rate variability assessment, developed by the Faculty of Physical Culture, were applied for the first time to examine patients with the history of atrial fibrillation.