Biomedical subjects

Heinz F Pitschner

Publications and source records attributed to Heinz F Pitschner.

8 recordsLinked to original sources

PubMed2005

Contractile response and mitral regurgitation after temporary interruption of long-term cardiac resynchronization therapy.

AIMS: Cardiac resynchronization therapy (CRT) utilizing biventricular pacing (BVP) is a promising treatment modality for symptomatic patients with chronic left ventricular (LV) systolic dysfunction and intraventricular conduction delay. Clinical studies have shown short-term improvement in contractile function and mid-term improvement in clinical status with CRT. The objective of this study was to evaluate the haemodynamic consequences of temporary interruption of CRT after long-term stimulation. METHODS AND RESULTS: Twenty patients (16 men, 4 women) with LV dysfunction and New York Heart Association class III or IV heart failure, despite optimal medical therapy and a QRS interval of at least 120 ms, received a transvenous BVP system at the age of 66 (interquartile range, 61-69). Patients were studied after a median duration of 427 days (interquartile range, 281-563) of continuous CRT and again 72 h after cessation of BVP. Withdrawal of CRT resulted in a significant decline in maximal rate of LV systolic pressure rise from 711 mmHg/s (interquartile range, 640-816) to 442 mmHg/s (interquartile range, 389-582) (P=0.0001) and increases in mitral effective regurgitant orifice area from 4.8 mm(2) (interquartile range, 0.0-7.8) to 9.1 mm(2) (interquartile range, 5.7-13.3) (P=0.0001), mitral regurgitant volume from 7.8 mL (interquartile range, 0.0-11.5) to 16.0 mL (interquartile range, 10.7-20.8) (P=0.0001) and fraction from 13.8% (interquartile range, 0.0-19.2) to 27.7% (interquartile range, 14.6-34.0) (P=0.0002) determined by Doppler echocardiography. CONCLUSION: Cessation of long-term BVP leads to a decline in LV systolic performance and an increase in functional mitral regurgitation. These results indicate a sustained benefit of long-term CRT and support the notion to maintain CRT indefinitely.

Aged↗

PubMed2005

A decrease in pulmonary vein diameter after radiofrequency ablation predicts the development of severe stenosis.

A decrease in ostial pulmonary vein (PV) diameter was observed in patients on the day after radiofrequency ablation of atrial fibrillation (AF). This study examined whether a relative reduction in PV diameter on day 1 (RRPVD1) after the procedure predicts the late development of severe PV stenosis (PVS). The study included 104 consecutive patients (mean age = 55 years, range 46-61, 34 women) with drug refractory AF. Pulmonary vein diameter was measured using MR angiography (MRA) on the day before and on day 1 after the ablation procedure. The MRA was repeated every 3 months after the procedure. Severe PVS was defined as a >70% diameter reduction from the initial ostial diameter. The cut-off of RRPVD1 was prespecified as 25% decrease in initial diameter. The data are presented as medians and interquartile range. A total of 357 PV were treated. The RRPVD1 was 0.0% (0.0-11.1%). Severe PVS was found in 18 PV during a follow-up of 12 months (range 6-13). The log-rank analysis confirmed a strong association between a RRPVD1 >/=25% and the development of PVS (hazard ratio: 7.1; 95% confidence interval 3.8-13.5, P < 0.0001). By multivariate Cox regression model, after adjustment of procedure variables, RRPVD1 was the strongest predictor of development of severe PVS. RRPVD1 >/=25% was a strong independent predictor of development of severe PVS.

Aged↗

PubMed2005

Usefulness of atrial fibrillation burden as a predictor for success of pulmonary vein isolation.

BACKGROUND: The definition of symptomatic improvement after pulmonary vein isolation (PVI) is controversial. We assessed primarily the usefulness and predictive accuracy (PA) of AF (atrial fibrillation) burden (AFB) within the first 3 months after the procedure as an early predictor for curative success as well as reduction of symptoms. METHODS: We studied 100 pts (62 men, mean age: 54 +/- 9 years, LVEF: 57 +/- 9%, paroxysmal AF, 85, persistent AF, 15) who underwent PVI. RF ablation was used in 63 patients. The combination of cryoablation and RF (Hybrid therapy) was used in the remaining 37 patients, in 19 patients of whom additionally linear lesions were performed. All patients were followed up 3 months after PVI (the blanking period) and every 3 months thereafter. The significance of early recurrence of AF (ERAF) was separately analyzed for RF and for hybrid therapy arm. Quality of life (QoL) was assessed using the physical composite summary score (PCS) and mental composite summary score (MCS). AFB was dichotomized at: 0, 0.5, 1, 6, 12, and 24 hours. RESULTS: ANOVA revealed significant differences between PCS at baseline and after PVI in patients without recurrence and with those with postablation AFB <12 hours. There was no difference between PCS in patients with AFB > or =12 hours within a 3 months interval and PCS at baseline. ERAF occurred in 35% of patients (16 patients, AFB > or =12 hours). Symptomatic ERAF occurred in 29 patients (17 patients AFB > or =12 hours). After the blanking period, documented AF recurrence was found in 50 patients (17 patients, AFB > or =12 hour). Symptomatic late recurrence was found in 47 patients (31 patients with AFB > or =12 hours). Absence of ERAF was revealed to be predictive for long-term success and symptomatic ERAF was found to be predictive for symptomatic AF recurrence (P <0.0001). CONCLUSION: AF recurrence with AFB > or =12 hours within 3 months is associated with a missed improvement of QoL. Symptomatic ERAF predicts recurrence independently of therapy.

Analysis of Variance↗

PubMed2004

Risk stratification using heart rate turbulence and ventricular arrhythmia in MADIT II: usefulness and limitations of a 10-minute holter recording.

BACKGROUND: We evaluated the usefulness of heart rate turbulence (HRT) parameters and frequency of ventricular premature beats (VPBs) for risk-stratifying postinfarction patients with depressed left ventricular function enrolled in Multicenter Automatic Defibrillator Trial II (MADIT II). METHODS: In 884 MADIT II patients, 10-minute Holter monitoring at enrollment was used to evaluate HRT parameters and frequency of VPBs. The primary endpoints were defined as all-cause mortality in patients randomized to conventional treatment and as appropriate therapy for ventricular tachycardia or fibrillation in patients randomized to implantable cardioverter defibrillator (ICD) therapy. RESULTS: The median turbulence slope was lower in patients who died in comparison to survivors in the conventional arm (2.3 vs 4.5 ms/RR; P < 0.05); but it was not a significant predictor of mortality after adjustment for clinical covariates (age, ejection fraction, beta-blocker use, and BUN levels). There was no association between HRT parameters and arrhythmic events in ICD patients. Conventionally treated patients who died and ICD patients who had appropriate ICD therapy had significantly more frequent VPBs than those without such adverse events. After adjustment for clinical covariates, frequent VPBs>3/10 min were associated with death in the conventional arm (HR = 1.63; P = 0.070) and were predictive for appropriate ICD therapy in the ICD arm (HR = 1.75; P = 0.003). CONCLUSION: In postinfarction patients with severe left ventricular dysfunction, frequent VPBs are associated with increased risk of mortality and with appropriate ICD therapy. HRT obtained from 10-min Holter ECG showed a trend toward the association with mortality in univariate analysis but HRT parameters were not predictive of the outcome in multivariate analyses.

Adult↗

PubMed2004

Decreased pulmonary perfusion in pulmonary vein stenosis after radiofrequency ablation: assessment with dynamic magnetic resonance perfusion imaging.

STUDY OBJECTIVES: The functional impact of pulmonary vein (PV) stenosis on pulmonary perfusion after radiofrequency ablation (RFA) for atrial fibrillation (AF) has not been systematically evaluated previously. Therefore, we correlated magnetic resonance (MR) pulmonary perfusion imaging with single-photon emission CT (SPECT) perfusion and with the degree of PV stenosis (PVS) apparent on MR angiography (MRA) after RF ablation. SETTING: Joint radiology-cardiology collaborative magnetic resonance unit at the Kerckhoff Heart Center. DESIGN AND PATIENTS: This was a cohort study of 110 patients who were routinely examined by MRA after RFA for AF, whereby 51 patients with a PV diameter reduction of > 25% or with clinical symptoms (ie, dyspnea and cough) were enrolled into the study. Patients were examined at follow-up by MR perfusion imaging and MRA, and the results were compared to those from patients who underwent SPECT scanning and from a control group of 26 untreated patients. Twelve patients underwent PVS dilatation as well as 22 sequential follow-up examinations. METHODS: Pulmonary perfusion was evaluated using a dynamic contrast-enhanced three-dimensional MR perfusion sequence (1.5 T, 2.5-s temporal resolution, and 0.05 cm spatial resolution), and high-resolution, contrast-enhanced MRA was performed to measure PV diameter. PV dilatation was performed using an angioplasty catheter that was 8 to 10 mm in diameter. RESULTS: The localization and extent of perfusion defects measured by MRI or SPECT scanning were precisely matched. MR perfusion imaging detected 20 of 21 perfusion defects (sensitivity, 95.2%; specificity, 100%). PVSs and perfusion deficits correlated closely and showed the following threshold: perfusion decreased substantially in PVs 6 mm in diameter. After PVS dilatation, perfusion was restored partially after weeks, and complete normalization was seen in 4 of 12 patients (33%). CONCLUSIONS: PVSs caused severe perfusion deficits, which were reliably demonstrated by MR perfusion imaging. Clinical symptoms correlated better with MR perfusion than they did with MRA. The combination with MRA to assess underlying PVS allowed a "one-stop-shopping" MRI procedure to be carried out. The results led to alterations of RFA techniques, and therefore MRA and MR perfusion imaging may be beneficial in patient follow-up and in evaluating new ablation techniques.

Atrial Fibrillation↗

PubMed2003

Microwave, irrigated, pulsed, or conventional radiofrequency energy source: which energy source for which catheter ablation?

The aim of the study was to compare the diameter of endomyocardial lesions induced with the delivery of microwave, cooled, or pulsed energy versus conventional RF energy. In vitro tests were performed in fresh endomyocardial preparations of pig hearts in a 10-L bath of NaCl 0.9% solution at 37 degrees C and constant 1.5 L/min flow. Ablation 7 Fr catheters with 4-mm tip electrodes were used, except for the delivery of microwave energy. Energy delivery time was set to 60 s/50 W in all experiments. Cooled energy delivery was performed with a closed irrigation catheter. Pulsed energy delivery was performed using a special controller with a duty-cycle of 5 ms. Microwave energy was delivered with a 2.5-GHz generator and 10-mm antenna. Electrode temperature and impedance were measured simultaneously. After ablation, lesion length, width, and depth were measured with microcalipers, and volume calculated by a formula for ellipsoid bodies. Each energy delivery mode was tested in ten experiments. The deepest lesions were created with cooled energy delivery, and the largest volume by microwave energy delivery. Pulsed RF produced significantly deeper lesions than conventional RF energy delivery. Cooled or pulsed RF energy delivery created deeper transmural lesions than conventional RF. To create linear lesions at anatomically complex sites (isthmus), microwave energy seemed superior by rapidly creating deep and long lesions.

Animals↗

PubMed2003

Quality-of-life in patients with paroxysmal atrial fibrillation after catheter ablation: results of long-term follow-up.

Paroxysmal atrial fibrillation (PAF) significantly impairs patients' quality-of-life (QOL). The effect on QOL of recently developed ablation techniques with curative intention has not been studied. Thirty patients (21 men, age 54.1 +/- 9.5 years) with PAF (duration 5.6 +/- 5.2 years) who failed antiarrhythmic (3.8 +/- 1.2 trials) drug therapy underwent catheter ablation. The follow-up time was 33.9 +/- 11 months. QOL was assessed preablation, 3, 6, 9, 12, 24, and 36 months after catheter ablation. The Medical Outcomes Survey Short-Form (SF-36), scored on a 0-100 scale for each of eight domains: bodily pain, general health, mental health, physical functioning, role-emotional, role-physical, social functioning, and vitality, was used. Simultaneously, patients filled out a symptom-specific checklist (SSC) with seven clinical items scored 1-4 (1 best): dyspnea, nausea, palpitations, anxiety, syncope, presyncope, and NYHA classification. Patients with successful catheter ablation had a significant benefit in seven of eight subscales while patients with recurrence had an impact on QOL in two of eight subscales. Using SSC, a successful ablation influenced scores in all seven items while patients with recurrence had a significant change of clinical symptoms in only one item, anxiety. The subscales of the study group compared to a healthy population show higher scores after 24 months of follow-up. Patients with PAF experience a significant improvement in QOL after a successful catheter ablation. In contrast, in patients with recurrence of PAF the QOL showed improvement to a lesser extent and patients experienced ongoing symptoms.

Atrial Fibrillation↗

PubMed2002

Shock coordinated with high power of morphology electrogram improves defibrillation success in patients with implantable cardioverter defibrillators.

Animal studies have suggested that the success of defibrillation may depend on the properties of VF waveform obtained from the morphology electrogram (ME) at the time of the shock. The reliable identification of depolarization events in the fibrillatory signal can be achieved using adaptive estimation of the instantaneous signal power (P). The aim of this study was to investigate if a high P of the ME (P(ME)) was related to ventricular DFT and if the upslope in ME can be associated with the depolarization event. A total of 575 VF (mean duration 10 s) episodes recorded and stored during ICD implantation in 77 patients with ventricular arrhythmias were used for analysis. The DFT was defined using a double step-down test. The values of P(ME) immediately before pulse delivery (P(shock)) and shock outcomes were registered. The differences between P(shock) of successful and failed defibrillation were tested with the Mann-Whitney U test. The relationship between individual medians of P(shock) (P(med)) and DFT was analyzed using the Kruskall-Wallis H-test. The coincidence between identified depolarization and upslope in ME was tested using the chi-square test. A P value of 0.05 was set for an error probability. The P(shock) in case of failed defibrillation was significantly lower than P(shock) in successful cases by the pulses of any strength (P < 0.001). The test revealed a significant inverse correlation between P(med) and DFT with P < 0.001. The depolarization corresponded to the upslope of ME in 85% of cases. This study demonstrated that a high value of instantaneous power of ME indicates the optimal time for shock delivery. The implementation of this algorithm in ICDs may improve the defibrillation efficacy.

Algorithms↗