AIMS: Electrical storm (ES) adversely affects prognosis of patients and may become a life-threatening event. Catheter ablation (CA) has been proposed for the treatment of ES. Our goal was to evaluate the efficacy of CA ablation both in acute and long-term suppression of ES. METHODS AND RESULTS: Fifty consecutive patients with coronary artery disease (38), idiopathic dilated cardiomyopathy (5), arrhythmogenic right ventricular cardiomyopathy (6), and/or with combined aetiology (1) underwent CA for ES. Mean left ventricular ejection fraction (LVEF) was 29 ± 11%. All patients underwent electroanatomical mapping, and CA was performed to abolish all inducible ventricular arrhythmias. The ES was suppressed by CA in 84% of patients. During the follow-up of 18 ± 16 months, 24 patients had no recurrences of any ventricular tachycardia (VT; 48%). Repeated procedure was necessary to suppress the recurrent ES in 13 cases (26%). Statistical analysis revealed that low LVEF (22 ± 3 vs. 31 ± 12%; P < 0.001), increased LVend-diastolic diameter (72 ± 9.1 vs. 64 ± 8.9 mm; P = 0.0135), and renal insufficiency (P < 0.001) were the univariate predictors of early mortality or necessity for heart transplantation. Recurrence of ES despite previous CA procedure was associated with a higher risk of death or heart transplant during follow-up (P < 0.05). CONCLUSION: Catheter ablation is effective in acute suppression of ES and often represents a life-saving therapy. In the long term, it prevents recurrences of any VT in about half of the treated patients.

• MeSH
• dilatační kardiomyopatie komplikace   epidemiologie   MeSH
• fibrilace komor epidemiologie   mortalita   chirurgie   MeSH
• Kaplanův-Meierův odhad MeSH
• katetrizační ablace * MeSH
• komorbidita MeSH
• komorová tachykardie epidemiologie   mortalita   chirurgie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• následné studie MeSH
• nemoci koronárních tepen komplikace   epidemiologie   MeSH
• nemoci srdce komplikace   epidemiologie   MeSH
• retrospektivní studie MeSH
• senioři MeSH
• srdeční arytmie komplikace   epidemiologie   MeSH
• výsledek terapie MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Compared to the natural electrical activation of the myocardium through the His-Purkinje system, right ventricular pacing is associated with prolonged QRS complex duration, thereby impeding the synchronicity of contractions. In left ventricular pacing, a higher pacing voltage decreases the QRS complex duration. The aim of our study was to describe the relation between the right ventricular pacing voltage and the QRS complex duration. Fourteen patients (73.6 +/- 7.6 years) with AV block and implanted pacemakers were paced at a frequency of 100 bpm with various pacing voltages. A signal-averaged QRS vector length was calculated at each degree of pacing voltage. The changes in the QRS complex duration were measured as a relative shift of the terminal region of the vectorcardiographic QRS complex (end-shift) and its most prominent peak (peak-shift) using the cross-correlation method. The nonlinear relationship between stimulation voltage and QRS duration was observed with the highest impact of stimulation voltage changes near the threshold value. The fourfold increase in the stimulation voltage above the threshold caused QRS complex shortening by 3.7 +/- 2.1 ms (range 0.19-7.76 ms). Similar peak- and end-shift responses to altered stimulation energy demonstrated that the acceleration of depolarization occurred in the initial portion of the QRS complex. Older electrodes exhibited smaller and more linear changes in the QRS complex duration.

• MeSH
• funkce pravé komory srdeční * MeSH
• kardiostimulace umělá * MeSH
• lidé středního věku MeSH
• lidé MeSH
• modely kardiovaskulární * MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• vektorkardiografie * MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: Decrease in neurohormonal activation during pharmacotherapy for chronic heart failure (CHF) is associated with haemodynamic and clinical improvement. We tested the hypothesis that changes in neurohormonal activation after initiation of cardiac resynchronization therapy (CRT) predict its long-term clinical effect. METHODS: The study group included 43 patients with CHF (37 males, mean age 62+/-9 years, NYHA class 3.2+/-0.4, QRS duration 195+/-24 ms) who underwent successful implantation of a CRT system. Pharmacotherapy remained stable during the first 3 months of follow-up. Plasma levels of B-type natriuretic peptide (BNP) and big endothelin-1 (big ET-1) were evaluated before and 3 months after implantation. Clinical, echocardiographic and exercise parameters were monitored for a mean period of 25.8+/-6.7 months. RESULTS: At 12 months of follow-up 13 non-responders were identified (no improvement in NYHA class (n=10), urgent heart transplantation (n=2) and death due to progressive heart failure (n=1)). CRT resulted in a significant reduction in neurohormone levels (BNP 345.4+/-346 vs. 267.7+/-320.8 pg/ml, p<0.01, big ET-1 3.11+/-1.50 vs. 2.50+/-1.56 fmol/ml p<0.05), especially in responders. Percentage change in BNP level was a stronger predictor of long-term clinical improvement than clinical, echocardiographic and exercise parameters at 3 months of follow-up. CONCLUSIONS: Percentage change in plasma BNP levels from baseline to 3 months was the strongest predictor of long-term response to CRT and may have potential to predict outcome.

• MeSH
• biologické markery MeSH
• časové faktory MeSH
• dospělí MeSH
• kardiostimulace umělá * MeSH
• ledviny fyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• následné studie MeSH
• natriuretický peptid typu B krev   MeSH
• prognóza MeSH
• progrese nemoci MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• srdeční selhání krev   patologie   terapie   MeSH
• výsledek terapie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• biologické markery MeSH
• natriuretický peptid typu B MeSH

BACKGROUND: The benefit of biventricular pacing (BiV) may be substantially affected by optimal lead placement. AIM: To evaluate the importance of right ventricular (RV) lead positioning on clinical outcome of BiV. METHODS AND RESULTS: A total of 99 patients with symptomatic heart failure and implantation of BiV system were included. Position of the left-ventricular (LV) lead was selected based on timing of local endocardial signal within the terminal portion of the QRS complex. RV lead was preferably positioned at the midseptum (n=74, RVS group) where the earliest RV endocardial signal was recorded. A subgroup of patients had RV lead placed in the apex (n=25, RVA group). NYHA class, maximum oxygen-uptake (VO(2)max), LV end-diastolic diameter (LVEDD, mm) and ejection fraction were assessed every third month. A trend towards greater improvement in NYHA class and significant increase in VO(2)max was present in the RVS group. Moreover, a significant decrease in LVEDD (DeltaLVEDD) was observed in the RVS group only (-3.4+/-6.5 mm versus +1.7+/-6.4 mm in RVA group at 12 months, p=0.004). No significant correlation between the degree of DeltaLVEDD and QRS narrowing induced by BiV was found. LVEDD reduction was predominantly present in dilated cardiomyopathy. CONCLUSIONS: Midseptal positioning of the RV lead appears to promote reverse LV remodelling during cardiac resynchronisation therapy.

• MeSH
• chronická nemoc MeSH
• hypertrofie levé komory srdeční prevence a kontrola   MeSH
• implantované elektrody MeSH
• kardiostimulace umělá metody   MeSH
• kardiostimulátor * MeSH
• lidé středního věku MeSH
• lidé MeSH
• nízký srdeční výdej terapie   MeSH
• prospektivní studie MeSH
• remodelace komor MeSH
• srdeční komory inervace   MeSH
• srdeční septum inervace   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Biventricular pacing (BiV) is employed as the current standard for cardiac resynchronisation therapy. Other pacing modalities have been proposed as alternatives; however, data on changes in electrical activation sequence caused by pacing from various sites are limited. AIM: To describe changes in activation patterns during different ventricular pacing modes in patients with chronic heart failure. METHODS: A total number of 20 patients (mean age 59.6+/-8 years) with chronic heart failure, intraventricular conduction abnormality (QRS >130 ms) or complete AV block were studied. Endocardial activation maps of both ventricles (CARTOTM, Biosense-Webster) were obtained during spontaneous rhythm and biventricular (BiV, n=9), right ventricular bifocal (BiF, n=7) and single-site left ventricular (LV, n=4) pacing. The following parameters were assessed: activation pattern, total LV endocardial activation time (LVAT) and electrical interventricular delay (IVD). RESULTS: Right ventricular apical pacing was associated with the longest LVAT (145+/-24 ms). On the contrary, both BiV and BiF pacing shortened LVAT with BiV being superior in the degree of LVAT reduction (89+/-13 vs 103+/-10 ms, p<0.05). BiV pacing also significantly shortened IVD and modified the LV activation sequence in a complex manner. Such changes were not observed during BiF pacing. In the presence of fusion with spontaneous activation, single-site LV pacing was comparable to BiV pacing. CONCLUSIONS: Among the different pacing modes, BiV pacing and single-site LV pacing with fusion resulted in the most pronounced changes in ventricular activation that appear to be a prerequisite for successful resynchronization of both ventricles.

• MeSH
• dospělí MeSH
• dysfunkce pravé srdeční komory komplikace   patofyziologie   MeSH
• kardiostimulace umělá metody   MeSH
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• srdeční komory anatomie a histologie   patofyziologie   MeSH
• srdeční selhání etiologie   chirurgie   MeSH
• srdeční septum patofyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

From various points of view abandoned or displaced permanent pacemaker leads should be extracted in indicated cases using a broad spectrum of catheter-based techniques. We describe a relatively easy extraction procedure of almost the whole pacemaker lead, which broke near the pulse generator and migrated into right-heart chambers; so both ends were indwelling. The described procedure was undertaken using a simple homemade nitinol-based extractor.

• MeSH
• cizí tělesa terapie   MeSH
• implantované elektrody * MeSH
• kardiostimulátor * MeSH
• lidé MeSH
• odstranění implantátu MeSH
• selhání zařízení MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• slitiny MeSH
• syndrom chorého sinu terapie   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• Názvy látek
• nitinol MeSH Prohlížeč
• slitiny MeSH

OBJECTIVE: Some patients after myocardial infarction have an increased risk of malignant ventricular tachyarrhythmias (VTA) or sudden cardiac death. The aim of the study was to evaluate long-term results of surgical ablation of an arrhythmogenic substrate guided by simplified intraoperative mapping of pathological ventricular electrograms during sinus rhythm. METHODS: The study population consisted of 77 patients (9 women; mean age 62.4+/-8.5 years) with previous Q-wave myocardial infarction and at least one documented episode of sustained VT/VF more than one month after the last infarction. The left ventricular ejection fraction was 31.3+/-8.8%. All but eight patients had clinical indication for concomitant coronary artery bypass surgery. All underwent preoperative electrophysiologic study. Intraoperative epicardial and endocardial mapping during sinus rhythm was performed using a multielectrode with 16 bipolar electrodes in combination with a multichannel recording system. Myocardial regions revealing fractionated, low amplitude signals lasting > or =130 ms were surgically excised or cryoablated. All surviving patients were restudied within one to two weeks after surgery using identical programmed electrical stimulation protocol. RESULTS: Five (6.5%) patients died in the perioperative (30-days) period. In the remaining cohort, inducibility of any sustained VTA after surgical procedure was observed in 21 subjects (29.2%). An implantable cardioverter-defibrillator (ICD) was implanted in these patients. Recurrence of sustained VTA was documented during follow-up period in two patients who were noninducible after the surgery (at the month 10 and 22, respectively), and both received ICD as well. No patient died of sudden cardiac death. In 14 ICD patients, no significant VTA was documented during the mean follow-up of 37.3+/-23.2 months. Altogether, 61 from the 72 patients surviving the surgery (84.7%) remained free of spontaneous recurrences of VTA during the follow-up. CONCLUSIONS: Surgical ablation of an arrhythmogenic substrate guided by simplified intraoperative mapping in normothermic heart during sinus rhythm appears to be both safe and efficacious procedure that prevents recurrences of VTA in a substantial proportion of patients.

• MeSH
• defibrilátory implantabilní MeSH
• dospělí MeSH
• elektrokardiografie MeSH
• infarkt myokardu komplikace   mortalita   chirurgie   MeSH
• kardiochirurgické výkony metody   MeSH
• kohortové studie MeSH
• komorová tachykardie etiologie   mortalita   chirurgie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• pooperační komplikace etiologie   MeSH
• senioři MeSH
• výsledek terapie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Although cardiac resynchronization therapy (CRT) has clearly demonstrated its clinical benefit in patients with congestive heart failure (CHF) and intraventricular conduction abnormalities, selection of eligible patients and/or optimal pacing site are still a matter of debate. The aim of the study was to analyze the spectrum of conduction abnormalities in CRT candidates. A total of 26 patients (mean age 62 +/- 9 years) with CHF and conduction disturbances (QRS > or = 130 ms) were studied. The underlying heart disease was dilated cardiomyopathy (DCM) (n = 12) or coronary artery disease (CAD) (n = 14). High density, left ventricular endocardial activation maps were constructed using an electroanatomic mapping system (CARTO). Based on endocardial activation patterns, left ventricular conduction abnormalities were classified as left bundle branch block (LBBB) (n = 9), nonspecific intraventricular conduction disturbances (n = 10), and the bifascicular block (n = 7). In DCM patients the endocardial activation sequences corresponded with a 12-lead ECG pattern with a homogeneous spread of activation wavefront and the latest activation laterally (LBBB) or anteriorly (bifascicular block), respectively. CAD patients presented with variable activation patterns that reflected the location of the postinfarct scar, and the 12-lead ECG was less predictive. Although there was a trend for longer QRS durations for DCM subjects (170 +/- 23 vs 156 +/- 23 ms, P = NS), left ventricular activation time was significantly longer in the CAD group (115 +/- 21 ms vs 134 +/- 23 ms, P < 0.05). CRT candidates represent a broad spectrum of conduction abnormality patterns with variable inter- and intraventricular activation delays. CAD subjects have more pronounced intraventricular conduction abnormality. The standard ECG is less reliable in the characterization of complex conduction abnormalities.

• MeSH
• blokáda Tawarova raménka patofyziologie   MeSH
• dilatační kardiomyopatie patofyziologie   MeSH
• dospělí MeSH
• elektrokardiografie MeSH
• kardiostimulace umělá * MeSH
• koronární nemoc MeSH
• lidé středního věku MeSH
• lidé MeSH
• převodní systém srdeční patofyziologie   MeSH
• senioři MeSH
• srdeční selhání patofyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The goal of this study was to analyze total procedural and fluoroscopic time during initial experience with implantation of LV lead in a single center, and to assess the performance of electrophysiologically-guided approach for cannulation of the coronary sinus (CS) in a subsequent period. Over an initial period of 29 months, a total of 46 attempts to implant biventricular pacing system were revised. During the first phase, only one type of LV electrode was available for three implanters (11 attempts). The second phase covered their early experience with other stylet-controlled LV leads (10 attempts). Additional LV leads including the over-the-wire design were available in the third phase and 25 attempts were done by he most experienced implanter. In a period of advanced experience, 92 implant procedures performed by four implanters using an electrophysiologically-guided approach to CS cannulation were revised. In the first period, success rates for different phases reached 70%, 90%, and 96%, respectively. Significant decrease in both procedural and fluoroscopic times was achieved with increased experience (Phase I: 247.1 +/- 104.5 minutes and 31.2 +/- 34.3 minutes, Phase II: 219.4 +/- 85.6 minutes, and 22.9 +/- 19.1 minutes, Phase III: 116.4 +/- 89.9 minutes and 6.6 +/- 4.4 minutes, respectively, P < 0.05). Advanced experience with electrophysiologically-guided approach to CS cannulation allowed achievement of this target within a reasonable amount of time (15.4 +/- 16.3 minutes) and with minimum fluoroscopic time (2.1 +/- 2.9 minutes). In conclusion, both individual learning curve and technical advances significantly influence success rate, procedural, and fluoroscopic times for biventricular system implantation. Electrophysiologically-guided approach makes cannulation of the CS a highly reproducible procedure that requires minimum fluoroscopic time.

• MeSH
• analýza rozptylu MeSH
• dospělí MeSH
• elektrokardiografie * MeSH
• fluoroskopie MeSH
• implantované elektrody * statistika a číselné údaje   MeSH
• kardiostimulátor * statistika a číselné údaje   MeSH
• klinické kompetence MeSH
• lidé středního věku MeSH
• lidé MeSH
• reprodukovatelnost výsledků MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• srdeční selhání patofyziologie   terapie   MeSH
• statistika jako téma MeSH
• studie pohybu a času MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

From the point of view of established practice, redundant permanent pacing leads have been abandoned or extracted using various catheter-based procedures. An unusual complication was caused by failed surgical lead extraction resulting in electrode severing and wire unbraiding with subsequent induction of electric interaction between the metallic, noninsulated part of the lead fragment and the defibrillating electrode. This interaction was sensed and detected by the ICD system. A modified catheter-based extraction procedure is described.

• MeSH
• cizí tělesa terapie   MeSH
• dospělí MeSH
• implantované elektrody MeSH
• kardiostimulátor * MeSH
• lidé MeSH
• odstranění implantátu MeSH
• selhání zařízení MeSH
• srdeční katetrizace přístrojové vybavení   metody   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH