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.

[Correlation of intracardiac pressures and electrical atrial potentials with morphology and function of overloaded atria assessed by echocardiography]. / Korelace intraatriálních elektrických potenciálu a tlaku s morfologickými a funkcními ukazateli pretízených síní stanovenými echokardiografií.

BACKGROUND: In patients with chronic complete heart block or single chamber pacing and preserved sinus depolarization, left and right atria (LA, RA) may suffer from increased intraatrial pressure resulting from atrioventricular dyssynchrony (AVDys), dilate and lose their contractile function. The purpose of the study was to find out whether any correlation exists between the echocardiographically measured LA, RA morphological and functional parameters on one hand and the intracardiac RA pressures and electrical potentials on the other hand in patients with chronic AVDys. METHODS: In 26 pts (77 +/- 10 years, 16 males), where a chronic AVDys was the most important patophysiological mechanism of atrial overloading, the intraatrial pressures (atrial, right ventricular, pulmonary arterial and wedge pressure/PWP/) and electrical potentials (upper, middle, lower part of RA and RA appendage) were correlated with atrial diameters, volumes, ejection fraction and filling parameters. RESULTS: There was a moderate inverse correlation between the LA ejection fraction and PWP: r = -0,489, p = 0,025 at a level of significance 0.05, but no relationship between PWP and LA size/volumes. No correlation between RA potentials or intracardiac pressures and RA morphologic or functional features were documented. CONCLUSIONS: In this study, an inverse correlation between the capillary wedge pressure and left atrial ejection fraction in pts with chronic atrioventricular dyssynchrony was documented. No other correlation between echocardiographic parameters and intracardiac pressures or electrical potentials was found.

Similar long-term benefits conferred by apical versus mid-septal implantation of the right ventricular lead in recipients of cardiac resynchronization therapy systems.

INTRODUCTION: The benefits conferred by cardiac resynchronization therapy (CRT) are markedly influenced by the left ventricular (LV) lead placement. Little is known regarding the optimal right ventricular (RV) stimulation site. STUDY OBJECTIVE: To compare the long-term outcomes of CRT in patients with RV leads placed in the mid-septal region versus the apex. METHODS AND RESULTS: This nonrandomized, observational study included 117 patients with standard indications for CRT. The LV lead was implanted on the postero-lateral or lateral LV wall, while the RV lead was implanted at the apex (n = 82) or in the mid-septum (n = 35). Both groups were similar with respect to baseline clinical, demographic, and echocardiographic characteristics. After 12 months of CRT, the rates of clinical response to CRT were similar in both groups (63% vs. 66%), and similar degrees of reverse LV remodeling and LV resynchronization were observed on echocardiography and color tissue Doppler imaging. A > or =30% relative increase in LV ejection fraction (EF) occurred in 76% of patients in the RV apex group, versus 49% of patients in the RV mid-septum group (P = 0.05). A > or =45% left ventricular ejection fraction (LVEF) was measured at 12 months in 40% of patients in the RV apex group, versus 31% in the RV mid-septum group (ns). CONCLUSIONS: RV mid-septal stimulation was not associated with a higher rate of response to CRT or greater improvement in LV function compared to RV apical stimulation.

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.

Usefulness of bifocal pacing in patients with heart failure and intraventricular conduction delay.

BACKGROUND: Bifocal pacing (BFP) has been proposed as a feasible alternative to cardiac resynchronization therapy. AIM: To evaluate BFP in patients with severe heart failure and significant intraventricular conduction delay and to compare it with biventricular pacing (BVP). METHODS: Echocardiographic examination including TDI and invasive measurement of haemodynamics was performed under basal conditions, during BFP and during BVP. RESULTS: Fifty patients were included: 29 with ischaemic heart disease (IHD), 21 with idiopathic dilated cardiomyopathy (IDCM). LV dp/dt(max) increased during BFP compared to the basal state (13.4%, 95% CI 9.2-17.6%, p<0.0001) and a further increase was achieved during BVP (29.5%, 95% CI 23.7-35.4%, p<0.0001). A significant correlation was found between the distance of the right ventricular apical and outflow tract leads and percentage of dp/dt(max) increase in IDCM patients (r=0.72), but not in IHD patients. Interventricular mechanical delay (IVMD) decreased in BFP (43+/-22 ms vs. 53+/-31 ms, p=0.006), but BVP produced even shorter IVMD (22+/-19 ms, p<0.0001). In all patients, regional systolic contraction times were significantly shortened, corresponding with prolongation of the respective regional diastolic filling times during both BFP (p<0.05 for all segments) and BVP (p<0.001 for all segments). CONCLUSIONS: BFP improves LV haemodynamics by decreasing the inter- and intraventricular conduction delays. The leads in the right ventricle should be placed at the longest achievable distance. BVP is superior to BFP.

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.

Bifocal pacing - A novel cardiac resynchronization therapy? Results of bifocal pacing study and review of the current literature.

BACKGROUND: Bifocal pacing (BFP) has been proposed as a more feasible alternative of cardiac resynchronization therapy (CRT). AIM: To evaluate BFP in patients with severe congestive heart failure and significant intraventricular conduction delay and to compare it with biventricular pacing (BVP). METHODS: Both echocardiographic examination including tissue Doppler imaging and invasive measurements of cardiac hemodynamics was performed under basal conditions and during BFP and BVP. RESULTS: 50 patients were included: 29 patients with ischemic heart disease (IHD), 21 patients with idiopathic dilated cardiomyopathy (IDCM). Left ventricular (LV) pressure gradient (dp/dt max) increased during BFP compared to the baseline (13.4 %, 95 % CI 9.2-17.6 %, p < 0.0001) and a further increase was achieved during BVP (29.5 %, 95 % CI 23.7-35.4 %, p < 0.0001). A significant correlation was found between the distance of the right ventricular apical and outflow tract leads and percentage of dp/dt max increase in IDCM patients (r = 0.72, p < 0.001), but not in IHD patients. Interventricular mechanical delay (IVMD) decreased in BFP compared to baseline (43 +/- 22 ms vs. 53 +/- 31 ms, p = 0.006). BVP produced even shorter IVMD (22 +/- 19 ms, p < 0.0001). In all patients, the regional systolic contraction times were significantly shortened, corresponding with prolongation of the respective regional diastolic filling times during both BFP (p < 0.05 for all segments) and BVP (p < 0.001 for all segments). The effect of BVP on regional systole shortening was more pronounced. CONCLUSIONS: BFP improves LV hemodynamics by decreasing the inter- and intraventricular conduction delays. The leads in the right ventricle should be placed at the longest achievable distance. BVP is superior to BFP.

Acute severe mitral regurgitation with cardiogenic shock caused by two-step complete anterior papillary muscle rupture during acute myocardial infarction.

BACKGROUND: Rupture of a papillary muscle is an infrequent but often fatal mechanical complication of acute myocardial infarction. AIM: The aim of this paper is to present a case report of a 65-year old women with acute severe mitral regurgitation with cardiogenic shock caused by two-step complete anterior papillary muscle rupture during acute myocardial infarction. The transthoracic echocardiography was obtained at the bedside and showed a posterior mitral valve prolapse with a severe mitral regurgitation. During this examination the patient developed acute pulmonary oedema and a consequent cardiogenic shock. Transthoracic echocardiography was then reevaluated and completed. New findings of bi-leaflet mitral flail and progression of massive mitral regurgitation were documented. The complete rupture of a papilary muscle was then considered as a cause of an acute clinical deterioration. Intraoperative findings showed a complete transection of both heads of anterolateral and necrotic regions of basis of posteromedial papillary muscle. CONCLUSIONS: This case confirms the importance of immediate echocardiography in confirming a diagnosis of acute mechanical complications of acute coronary syndromes and this examination is important for the management of a hemodynamically unstable patient. Echocardiography should be done immediately on any patient in whom the diagnosis of mechanical complication of acute coronary syndromes is suspected.

Dramatically improved left ventricular function after biventricular pacemaker implantation--a case report.

A case study of a patient suffering from severe chronic congestive heart failure resulting from ischemic cardiomyopathy in whom a biventricular (BiV) pacing system was implanted is reported. After a 1-year follow-up, left ventricular (LV) ejection fraction improved dramatically from an initial 15% to 60%, left ventricular end-diastolic diameter decreased, as did left atrial dimension. Tissue Doppler data and acute hemodynamic measurements taken during the biventricular pacemaker implantation procedure are presented. The case represents an exceptional example of left ventricular reverse remodeling with practically normalized left ventricular function after 1 year of synchronized pacing.

Risk factors for cardiovascular diseases in physicians.

The aim of the study was to determine the prevalence of risk factors for cardiovascular diseases among physicians at a teaching hospital. In total, 203 men and 167 women were included in the study. The participants filled in a questionnaire; their height, weight, blood pressure, serum cholesterol and glucose levels were added. 19.2 % males and 13.8 % females were smokers, hypertension was diagnosed in 10 % of males and in 6.6 % of females, 52.2 % males and 17.4 % females were overweight, 37 % males and 43.1 % females had hypercholesterolemia. The above findings suggest that Czech physicians have more favourable values of all the studied cardiovascular diseases risk factors than the general Czech population. However, Czech physicians smoke more than those in other countries and their level of cardiovascular diseases risk factors is unsatisfactory and calls for further intensive prevention. Preliminary outcomes of the study repeated after two years show no positive trends as well as physicians' low willingness to actively participate in lowering cardiovascular diseases risk factors.

CC chemokine receptor (CCR)2 polymorphism in Czech patients with myocardial infarction.

Examining an association between myocardial infarction (MI) and the Val/Ile polymorphism in the gene for CC chemokine receptor (CCR)2 at the position 64 (CCR2-V64I), 122 MI Czech patients and 277 unrelated control (C) subjects were genotyped by PCR-SSP. The frequency of the VI genotype of CCR2-V64I was increased in MI patients in comparison with the control population (P=0.03). Further analysis revealed that relationship between the VI genotype and MI is specific only for females and, strikingly, this genotype was associated to an early MI onset (before or at the age of 50 years). Females with the VI genotype were seven times more prone to suffer from MI before 50 years than those with the VV genotype (P<0.01). If the VI genotype of the CCR2-V64I is indeed a risk factor for an earlier MI onset in females must be checked by independent studies in other centres and/or populations.

Endothelial damage and activation of the hemostatic system during radiofrequency catheter isolation of pulmonary veins.

AIMS: To determine the systemic thrombogenic effect of radiofrequency catheter isolation of the pulmonary veins (PVI) in the treatment of atrial fibrillation. METHODS AND RESULTS: We studied endothelial damage marker (von Willebrand factor [vWf]), fibrinolysis markers (tissue plasminogen activator [t-PA], plasminogen activator inhibitor-1 [PAI-1]) and coagulation activation markers (D-dimer [DD]) in 30 patients (pts) undergoing PVI. Heparin was administered continuously after double transseptal puncture in all pts. Concentrations of vWf and t-PA were significantly increased after accomplishing PVI compared to the baseline values, and elevated levels persisted 24 hours later ( p < 0.01). PAI-1 levels decreased following PVI compared to the baseline levels ( p = 0.02). PAI-1 levels normalized 24 hours after the procedure. DD increased continuously during the procedure with the peak following PVI ( p < 0.01). Higher DD concentrations persisted 24 hours later ( p = 0.02). In a multivariate analysis, total procedure time correlated significantly with the peak vWf and DD concentrations, while total RF energy dose correlated only with peak vWf ( r = 0.82). Time to heparin administration correlated with DD levels prior to the first RF pulse ( r = 0.83, p < 0.01) as well as after PVI ( r = 0.75, p < 0.01). A group of patients heparinized within the first hour of the PVI procedure had normal preablation DD levels and significantly mitigated DD levels following PVI compared to the group of patients heparinized later ( p < 0.01). CONCLUSIONS: Pulmonary vein ablations cause an increased systemic procoagulant state as reflected by fibrin turnover, fibrinolysis activation and endothelial perturbation. The activation of the coagulation cascade could be decreased by early heparin administration.

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.

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.

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.

Acute aortic dissection complicated by fistula from aorta to right ventricle through ventricular septum.

A case report of aortic dissection (AoD) complicated by a shunt to the right ventricle is presented. Complications, treatment options, and survival of patients with Type A and Type B AoD are reviewed.

The macrophage migration inhibitory factor (MIF) gene polymorphism in Czech and Russian patients with myocardial infarction.

BACKGROUND: Macrophage migration inhibitory factor (MIF) is a cytokine implicated in early and advanced atherosclerosis. The aim of this study was to investigate whether polymorphism of MIF gene is associated with myocardial infarction (MI). METHODS: Single nucleotide polymorphism (SNP) in MIF gene (-173G/C, rs755622) was investigated in Czech (n=219) and Russian (n=240) MI patients and population control from the same geographical areas (Czech, n=137; Russian, n=174). Further, another SNP (rs1007888) located within the 3' flanking region of the MIF gene was investigated in Czech MI patients and control subjects. RESULTS: There were no significant differences in the distribution of MIF -173G/C genotypes, alleles or carriage rates between case and control groups in either populations. However, the GG genotype of the MIF SNP rs1007888 was associated with MI in Czech female patients (p=0.027). CONCLUSIONS: Taken together with previous reports, our study suggests that particular MIF gene polymorphisms may contribute to MI susceptibility in females.