The Heart Failure Optimization Study (HF-OPT): rationale and design.

BACKGROUND: According to the current guidelines, implantable cardioverter-defibrillators (ICD) for primary prevention in patients with heart failure and reduced ejection fraction (HFrEF) should not be considered until optimal guideline-directed medical therapy (GDMT) has been achieved for a minimum of 3 months. Optimization of GDMT often needs time beyond 3 months after diagnosis. The aim of the Heart Failure Optimization Study (HF-OPT) is to evaluate the recovery of left ventricular function beyond 3 months after diagnosis of newly diagnosed HFrEF. METHODS: The HF-OPT multicenter study is comprised of two non-randomized phases (registry and study). During the first 90 days a wearable cardioverter-defibrillator (WCD) is prescribed and patients are enrolled in an observational pre-study registry. Registry subjects meeting inclusion criteria for the study portion at day 90 have ongoing left ventricular ejection fraction (LVEF) reassessment at 90, 180 and 360 days after the index hospital discharge, regardless of continued WCD use. Approximately 600 subjects will be enrolled in the study portion. Of those, one-third are anticipated to start the study phase at day 90 with reduced LVEF. The primary objective of this study is to observe the rate of recovery of LVEF > 35% between 90 and 180 days, while key secondary endpoints include mortality and WCD recorded arrhythmias and shocks. DISCUSSION: The HF-OPT study will provide important information on the rate of additional recovery of LVEF > 35%, between 90 and 180 days, in newly diagnosed HF with reduced LVEF patients being titrated with GDMT. The results of the study may impact indications for primary prophylactic ICD implantation.

[Constellations of findings and derived treatment interventions in telemedical monitoring of patients with heart failure, cardiac arrhythmia or increased risk for sudden cardiac death : Recommendations of the working group 33 telemonitoring of the German Cardiac Society]. / Befundkonstellation und abgeleitete Behandlungsinterventionen bei telemedizinisch überwachten Patienten mit Herzinsuffizienz, Herzrhythmusstörungen oder erhöhtem Risiko für den plötzlichen Herztod : Empfehlungen der Arbeitsgruppe 33 Telemonitoring der Deutschen Gesellschaft für Kardiologie, Herz- und Kreislaufforschung e. V.

The specification of standard operating procedures (SOPs) is a basic requirement for a successful implementation of telemonitoring with implanted cardiac devices and with external measuring devices in patients with heart failure, cardiac arrhytmia or increased risk of sudden cardiac death. The following article summarizes the possibilities of telemonitoring from a technical and organizational point of view and descibes basic requirements on SOPs. these basic requirements should be further specified and anchored in the organizational structure of the individual telemonitoring concept. Moreover, they should de understood as a basic guideline fpr the actions of telemonitoring center (TMC) employees.

[Position paper telemonitoring : From the Nucleus Members of the AG33 Telemonitoring of the DGK and associated members]. / Positionspapier Telemonitoring : Von den Nukleusmitgliedern der AG33 Telemonitoring in der DGK und assoziierten Mitgliedern.

The position paper of the working group 33/Telemonitoring in the German Society for Cardiology e. V. (DGK) discusses the importance of digital solutions in the German health care system and highlights the application possibilities and potentials of telemonitoring in the treatment of patients with cardiac diseases. In addition to telemonitoring of acute ischaemic diseases, acute coronary syndrome and acute cardiac arrhythmias, telemonitoring of chronic cardiac diseases is discussed. Chronic diseases, such as chronic heart failure, are age-associated and present society with the great challenge of providing high-quality, yet cost-efficient care to an increasing number of patients in the future. Telemonitoring offers an opportunity to meet this challenge. However, the introduction of telemonitoring and the associated changes for patients, doctors and other service providers must be accompanied by measures to ensure the acceptance of telemonitoring and the secure handling of sensitive data as well as the quality of telemonitoring services.

[Basic structural features of a cardiac telemedicine center for patients with heart failure and implanted devices, cardiac arrhythmias, and increased risk of sudden cardiac death : Recommendations of the working group 33 Telemonitoring of the German Cardiac Society]. / Grundlegende Strukturmerkmale eines kardiologischen Telemedizinzentrums für Patienten mit Herzinsuffizienz und implantierten Devices, Herzrhythmusstörungen und erhöhtem Risiko für den plötzlichen Herztod : Empfehlungen der Arbeitsgruppe 33 Telemonitoring in der Deutschen Gesellschaft für Kardiologie, Herz- und Kreislaufforschung e. V.

Heart failure is one of the most common diseases. It is associated with high morbidity and mortality. Since heart failure is age-associated, the number of patients with heart failure is constantly increasing. At the same time, the imbalance between the need for treatment and the provision of care is growing. Telemonitoring/telemedicine offers patients in rural or remote areas access to high-quality health care and enables fast access to specialists. The working group 33 Telemonitoring of the German Cardiac Society describes the characteristics and possible applications of telemonitoring/telemedicine in the treatment of patients with heart failure. Furthermore, quality criteria for cardiological telemedicine centres are defined. In addition to the personnel structure of a telemedicine centre and the competencies of employees, requirements for the technical infrastructure and the management of incoming data and alarms are described.

[The telemedical service centre as an essential element of the conceptual approach for telemonitoring of cardiac patients : Requirements on the service, quality, and technical realization of telemonitoring]. / Das Telemedizinische Zentrum als essenzieller Baustein konzeptioneller Ansätze zum Telemonitoring kardialer Patienten : Anforderungen an Leistungen, Qualität und technische Umsetzung von Telemonitoring.

Telemonitoring as part of a treatment strategy supports and facilitates the monitoring, disease management and education of patients with heart failure and cardiac arrhythmias. Therefore, telemonitoring affects quality and success of the therapy. Thus, meeting the needs of the patients and of the involved health care professionals is important for the success of the telemonitoring service. Moreover, a high quality of the service has to be ensured. The following article describes several configuration options for telemonitoring services considering technical as well as quality- and service-related aspects.

[The Wearable Cardioverter-Defibrillator (WCD)]. / Der tragbare Kardioverter-Defibrillator.

While the implantable cardioverter-defibrillator (ICD) has been proven to be the best choice for patients with long-term risk for sudden cardiac arrest/sudden cardiac death (SCA/SCD), the question is how to manage patients with only temporary risk, e.g., during the guidelines-recommended waiting period until the decision for an ICD can be made. These patient groups should be monitored around the clock to guarantee a lifesaving shock within a few minutes, if necessary.These conditions can be accomplished by the wearable cardioverter-defibrillator (WCD) in the outpatient sector. The WCD is worn on the skin and consists of four nonadhesive ECG electrodes as well as three defibrillation electrodes-two at the back and one at the front-embedded in a garment. The defibrillation unit is connected via a cord and can be worn over the shoulder or on a belt. Cardiac events can be recorded and retrospectively analyzed by the treating physician.The WCD is a safe and effective measure to terminate potentially lethal ventricular tachycardia and ventricular fibrillation. It may be used early after myocardial infarction with reduced left ventricular ejection fraction (LVEF), as well as for patients with acute heart failure in nonischemic cardiomyopathy with uncertain cause and prognosis. In addition, it may be used for patients waiting for heart transplantation, for patients who cannot be implanted an ICD due to comorbidities, and for patients after explantation of their ICD, e.g., because of infection until reimplantation.One may expect that risk stratification of patients with the WCD will lead to even better selection for ICD use.

[Right atrial ablation of ectopic atrial tachycardia using a 20-pole mapping catheter]. / Ablation ektoper rechtsatrialer Tachykardien unter Verwendung eines 20-poligen Mapping-Katheters.

INTRODUCTION: Ectopic atrial tachycardia (EAT) are frequently unresponsive to pharmacological antiarrhythmic therapy. Radiofrequency ablation seems to be a safe approach to treat those arrhythmias. In the present study we report our results of radiofrequency ablation of EAT with a new mapping system (Stablemapr, Medtronic). METHODS: Thirty consecutive patients with right atrial tachycardia were included in the study. In 15 patients (G1) the 20-polar Stablemapr was used for localization of the arrhythmia foci. Data were compared with a control group (G2, n=15), in which mapping was performed conventionally. The demographic characteristics and the distribution of the different cardiac diseases were comparable in both groups. In group 1 the identification of the EAT was facilitated by the placement of the 20-pole mapping catheter in the right atrium. In group 2 point by point measurements were performed to find the earliest local atrial activation compared to a reference electrode in the high right atrium (activation mapping), or foci were identified by analysis of the P-wave morphology during stimulation (pacemapping). RESULTS: It was possible to successfully ablate all atrial tachycardias. The distribution of the foci was similar in both groups (G1/G2): near to the superior (3/5) and inferior (1/0) caval vene ostium, on the free wall (3/3), at the coronary sinus ostium (3/3) and on the interatrial septum (5/4). The mean procedure (G1: 88+/-33 vs G2: 151+/-61 min; p= or <0.05) and fluoroscopic times (G1: 19+/-9 vs G2: 38+/-28 min; p= or <0.05) were significantly shorter in group 1. Moreover, the mean number of radiofrequency applications was reduced significantly by using the new mapping system (G1: 10+/-10 vs G2: 16+/-13; p= or <0.05). CONCLUSION: Radiofrequency ablation of EAT with right atrial focus can be performed safely and successfully using a 20-pole mapping catheter. The greatest advantages compared to conventional mapping and ablation strategies lies in the shortened investigation and fluoroscopic time.

The RIONI study rationale and design: validation of the first stored electrograms transmitted via home monitoring in patients with implantable defibrillators.

Appropriate and inappropriate therapies of implantable cardioverter defibrillators (ICDs) have a major impact on morbidity and quality of life in ICD recipients. The recently introduced home monitoring of ICD devices is a promising new technique which remotely offers information about the status of the system. Stored intracardiac electrograms (IEGMs), which are essential for correct classification of appropriate and inappropriate ICD discharges, have until now not been available with ICD home monitoring on a day-by-day basis because of limitations of transferable data. We demonstrate the first compressed IEGMs daily transferable via home monitoring (IEGM-online). Validation of these electrograms will be performed in the Reliability of IEGM-Online Interpretation (RIONI) study. A total of 210 episodes of stored IEGMs will be collected by at least 12 European centres. The primary endpoint of this study is to investigate whether the IEGM-online based evaluation of the appropriateness of the ICDs therapeutic decision following episode detection is equivalent to the evaluation based on the complete ICD episode Holter extracted from the IEGM stored. The evaluation is independently done by an expert board of three experienced ICD investigators. The equivalence of the two methods is accepted if the evaluations yield a different conclusion for <10% of all evaluated IEGMs. The conclusion of the study is expected at the beginning of 2007. If RIONI successfully validates IEGMs transmitted via home monitoring, a strong basis for the use of this promising technique will be established.

IEGM-online based evaluation of implantable cardioverter defibrillator therapy appropriateness.

Appropriate and inappropriate therapies of implantable cardioverter defibrillators have a major impact on morbidity and quality of life in ICD recipients. Intracardiac electrograms (IEGMs) stored in the ICD have been shown to be essential for differentiating appropriate and inappropriate ICD therapies. The recently introduced third generation of ICD Home Monitoring offers remotely transmitted IEGMs (IEGM-online). Hence, the appropriateness of ICD therapies might be remotely assessed. Validation of these electrograms is currently being performed in the RIONI study. A total of 210 episodes will be collected by about 40 European clinical centers. The study primarily investigates whether the IEGM-online based evaluation of the appropriateness of the ICD's therapeutic decision following a tachyarrhythmia episode detection is equivalent to the evaluation based on the complete ICD episode holter. The evaluation is independently performed by an expert board of three experienced ICD investigators. The equivalence of the two methods is accepted if the conclusions deviate for less than 10% of all evaluated IEGMs. Secondary endpoints investigate the IEGM-online usefulness in more detail. The conclusion of the study is expected by mid of 2007. RIONI has successfully been started for proving the reliability of IEGM-online. The expected results will significantly influence the efficacy of Home Monitoring based patient management.

[The prediction of atrial fibrillation recurrence after electrical cardioversion with P wave signal averaged EKG]. / Die Prädiktion des Rezidives von Vorhofflimmern nach elektrischer Kardioversion mittels P-Wellen-Signalmittelungs-EKG.

METHOD: A P wave triggered and bidirectional P wave signal averaged ECG was used among 49 patients (35 m/14 w) 24 hours after electrical cardioversion. The measurements were only managed in sinus rhythm. Each patient was followed up for at least 6 months and the mean follow-up was of 9.1 months. RESULTS: A recurrence of atrial fibrillation was observed in 23 patients (47%) after a mean of 9,2 days (range 2-92 days). There was no difference in organic heart disease or in the use of drugs. The filtered P wave duration (FPD) was longer significantly (136.2 +/- 20.1 vs 119.5 +/- 19.8 ms, p < 0.0001) and the root mean square voltage of the last 20 ms of the P wave (RMS 20) was lower (2.77 +/- 1.10 vs 4.17 +/- 1.43 microV, p < 0.0001) in patients with a recurrence of atrial fibrillation. A cut-off point (COP) of FPD > or = 126 ms and RMS 20 < or = 3.1 microV achieved a specificity of 69%, a sensitivity of 74%, a positive predictive value of 68% and a negative predictive value of 75%. CONCLUSION: The results of our study suggest that the recurrence of atrial fibrillation after electrical cardioversion can be detected by P wave signal averaged ECG. The occurrence of COP seems to be a high risk factor of the recurrence of atrial fibrillation. The predictive power of the method has to be examined by prospective investigations of a larger patient population and a longer follow-up. The recurrence of atrial fibrillation after cardioversion has a high incidence. In our study, P wave signal averaged ECG was performed one day after successful electrical cardioversion in order to evaluate the utility of this method to predict atrial fibrillation after cardioversion.

[The prediction of atrial fibrillation recurrence after electrical cardioversion with the chemoreflex sensitivity]. / Die Prädiktion des Rezidives von Vorhofflimmern nach elektrischer Kardioversion mit der Chemoreflexsensitivität.

UNLABELLED: Patients with paroxysmal atrial fibrillation have a lower chemoreflex sensitivity (CHRS) which is characterized as an autonomic dysfunction. Because of this observation we examined the theory of an autonomic dysfunction as the reason for the reccurrence of atrial fibrilation after electrical cardioversion. METHOD: We measured the CHRS among 43 patients 24 h after successful electrical cardioversion and the patients were controlled for at least 6 months. RESULTS: During the six months of follow-up a recurrence was observed in 18 patients with a mean of 8.3 days. There was no difference in organic heart disease or in the use of drugs. Left atrial diameter was not significantly larger in patients with a recurrence. Patients with a recurrence have a significantly lower CHRS than patients with sinus rhythm (2.41 +/- 1.82 vs 5.62 +/- 3.02 ms/mmHg, p < 0.04). The diagnostic value of a CHRS below 3.0 ms/mmHg achieved a specificity of 68%, a sensitivity of 67%, a positive and negative predictive value of 60% and 74%. CONCLUSIONS: An analysis of CHRS seems to be an appropriate method to predict a recurrence of atrial fibrillation. The predictive power of the method has to be examined by prospective investigations of a larger patient population and a longer follow-up. Patients with paroxysmal atrial fibrillation have a lower chemoreflex sensitivity (CHRS) which is characterized as an autonomic dysfunction. Because of this observation we examined the theory of an autonomic dysfunction as the reason for the recurrence of atrial fibrillation after electrical cardioversion.

[Detection of atrial late potentials with P wave signal averaged electrocardiogram among patients with paroxysmal atrial fibrillation]. / Der Nachweis atrialer Spätpotentiale mittels P-Wellen-Signalmittelungs-EKG bei Patienten mit paroxysmalem Vorhofflimmern.

UNLABELLED: The analysis of the QRS-complex with signal averaged ECG (SAECG) has been evaluated for patients affected by ventricular tachycardia for a long time. A longer filtered QRS-complex was a marker of a slower ventricular conduction velocity and reentry tachycardia. This method was modified for an analysis of the P wave (P-SAECG). Different filter methods were evaluated for the analysis of atrial late potentials. METHOD: We measured the bidirectional P wave signal averaged ECG of 45 consecutive patients with (group A) and without (group B) paroxysmal atrial fibrillation (PAF) and 15 young volunteers without a cardiac disease (group C). RESULTS: As a result patients with PAF had a significantly lower root mean square voltage of the last 20 ms (RMS 20) (2.59 +/- 0.89) vs 4.08 +/- 1.45 microV, p < 0.0003) and a significantly longer filtered P wave duration (FPD) than patients of the control collective (139.2 +/- 17.5 vs 115.1 +/- 17.7 ms, p < 0.0001) and the young volunteers (3.44 +/- 0.95 microV, p < 0.0001/101.9 +/- 14.2 ms, p < 0.009). Furthermore we found an age-dependent relationship of FPD between group B and C (115.1 +/- 17.7 vs 101.9 +/- 14.2 ms, p < 0.05) but not an age-dependent relationship of the RMS 20 (4.08 +/- 1.45 vs 3.44 +/- 0.95 microV, p = n.s.). A specificity of 80% and a sensitivity of 78% was achieved for identifying patients with atrial fibrillation by using a definition of atrial late potentials as FPD > 120 ms and a RMS 20 < 3.5 microV. CONCLUSIONS: The analysis of the P-SAECG can be used as a non-invasive method for identifying atrial late potentials. Atrial late potentials might be a reason for PAF. The predictive power of atrial late potentials has to be examined by prospective investigations of a larger patient population.

[Determinants of paroxysmal atrial fibrillation in patients with arterial hypertension]. / Determinanten des paroxysmalen Vorhofflimmerns bei Patienten mit arterieller Hypertonie.

INTRODUCTION: Atrial fibrillation represents an important arrhythmia, in particular in patients with arterial hypertension. Hitherto, the connection between paroxysmal atrial fibrillation, left atrial size and left ventricular muscle mass has not been investigated sufficiently. In the present study, determinants of paroxysmal atrial fibrillation in patients with arterial hypertension were evaluated. METHODS: 104 consecutive patients were enrolled into this study. All of them suffered from arterial hypertension for more than one year. Persistent or permanent atrial fibrillation was not documented. In all of these patients, clinical, echocardiographic and rhythmologic variables were evaluated. RESULTS: In 10.3% of the patients, paroxysmal atrial fibrillation was found. These patients showed a significantly larger left atrium (43.3 +/- 6.7 vs 37.5 +/- 4.9 mm, p < 0.001), a significantly higher muscle mass of the left ventricle (152.38 +/- 43.57 vs 134.41 +/- 27.19 g/m2, p < 0.01) and significantly more frequent a mild mitral regurgitation (38.1 vs 28.6%, p < 0.01). The multivariate regression analysis revealed as independent factors for paroxysmal atrial fibrillation the size of the left atrium and the presence of mild mitral regurgitation. Independent factors for an enlarged left atrium were mitral insufficiency and left ventricular muscle mass. CONCLUSION: This study shows that paroxysmal atrial fibrillation in aterial hypertension is based on the left atrial size, and left atrial size on left ventricular muscle mass. Therefore, these results should lead to a causal therapy for treatment of paroxysmal atrial fibrillation in these patients.

Chemoreflexsensitivity among patients with paroxysmal atrial fibrillation.

UNLABELLED: Atrial fibrillation is the most common cardiac arrhythmia with typical complications of thromboembolisms. The autonomic nervous system is an important factor for the initiation of arrhythmias. A vagally or adrenergically hyperfunction could cause the initiation of paroxysmal atrial fibrillation (PAF). METHOD: We measured the chemoreflexsensitivity (CHRS) among 110 patients to determine a disturbed autonomic function as risk factor for PAF. We examined 45 patients with PAF (group A), 45 patients with sinus rhythm (group B) and 20 young volunteers (group C). The ratio between the difference of RR intervals in ECG and venous pO(2) was measured for the determination of CHRS. The margin of the CHRS was 3 ms/mmHg. RESULTS: Patients of group A had a significantly lower CHRS compared to group B (1.56+/-1.46 vs 6.29+/-3.71 ms/mmHg, p<0.0008) or group C (1.56+/-1.46 vs 6.35+/-4.29 ms/ mmHg, p<0.0003). A significant difference between group B and C could not be observed (6.29+/-3.71 vs. 6.35+/-4.29 ms/mmHg, p = n.s.). A specificity of 74% and a sensitivity of 71% was achieved for identifying patients with PAF by using a margin of 3 ms/mmHg for the CHRS. CONCLUSIONS: An analysis of CHRS seems to be an appropriate method to demonstrate a neurovegetative imbalance which might be one possible trigger mechanism of PAF. The predictive power has to be examined by prospective investigations of a larger patient population.

[Long-term follow-up of right atrial multilinear high-frequency ablation in the treatment of recurrent paroxysmal atrial fibrillation]. / Langzeitverlauf nach rechtsatrialer, multilinearer Hochfrequenzablation zur Behandlung von rezidivierendem paroxysmalem Vorhofflimmern.

BACKGROUND AND OBJECTIVE: To investigate the long-term follow-up after right atrial compartmentalization using radiofrequency catheter ablation to treat recurrent paroxysmal atrial fibrillation. PATIENTS AND METHODS: 33 patients (eight women / 25 men, mean age 56.1+/-9.9 years) with highly symptomatic recurrent paroxysmal atrial fibrillation and mostly unresponsive to antiarrhythmic drugs were enrolled in this prospective study. All patients underwent radiofrequency catheter ablation, including right atrial compartmentalization and ablation of the right atrial isthmus region. The primary goal during follow-up was documentation of arrhythmia-related symptoms using a SF-36 quality-of-life questionnaire. RESULTS: During a mean follow-up of 2.1 years 21 % of patients were free of a relapse under continued antiarrhythmic medication, 79 % suffered at least from one period of atrial fibrillation. According to the underlying heart disease patients classified as "lone atrial fibrillation" (40 % without a relapse) showed improvement particularly compared to patients with coronary heart disease (10 % without a relapse). In the group of patients with a relapse of atrial fibrillation the mean of duration of an arrhythmic episode decreased significantly from 10.6 to 2.3 hours under continued administration of antiarrhythmic drugs (p = 0.01), as did the number of episodes, from 2.2 to 1.9/week. CONCLUSION: Despite of the high rate of clinical relapse, patients can profit due to an improved responsiveness to antiarrhythmic drugs after ablation. Right atrial compartmentalization should not be understood as a causal therapy but as an approach to a symptomatic form of hybrid therapy.

Chemoreflexsensitivity in chronic heart failure patients.

AIMS: Patients with heart failure are characterised by a disturbed sympathovagal balance, as could be shown by analyses of heart rate variability and baroreflexsensitivity. Furthermore, the modulation of ventilation is disturbed in those patients with an increased ventilation volume following the inhalation of hypoxic gas. This study should evaluate, whether heart failure patients have a decreased hyperoxic chemoreflexsensitivity associated with an increased rate of ventricular arrhythmias. METHODS AND RESULTS: Into this study, 49 consecutive patients were enrolled. Of these, 23 suffered from heart failure; the remaining had no evidence of heart failure and a normal left ventricular ejection fraction. All patients were investigated by analysing the reduction of heart rate following inhalation of pure oxygen. The difference of RR-interval divided by the difference of the venous oxygen partial pressure both before and after oxygen inhalation resulted in the chemoreflexsensitivity. Patients with heart failure showed a significantly decreased chemoreflexsensitivity compared to those without (2.62+/-1.85 vs. 5.80+/-6.37 ms/mmHg, P<0.05). Of patients with heart failure, 69.6% had a decreased chemoreflexsensitivity below 3 ms/mmHg, in contrast to only 38.5% of the control group. Patients with decreased chemoreflexsensitivity showed significantly more non-sustained ventricular tachycardias (46 vs. 4%, P<0.05) during Holter ECG. CONCLUSION: Patients with heart failure show a significantly decreased hyperoxic chemoreflexsensitivity. A decreased chemoreflexsensitivity is associated with an increased rate of non-sustained ventricular tachycardias. This may be related to an increased sympathetic tone in these patients. The chemoreflexsensitivity may be important in arrhythmic risk stratification of patients with heart failure.

Comparative evaluation of thermodilution and gated blood pool method for determination of right ventricular ejection fraction at rest and during exercise.

BACKGROUND: Since the development of a Swan-Ganz thermodilution ejection fraction catheter several studies have been published which compare this technique for obtaining right ventricular ejection fraction (RVEF(TD)) with alternative methods. However, the reliability of RVEF(TD) measurements under exercise conditions remains undetermined. Therefore, the aim of the present study was a comparative evaluation of RVEF(TD) with the established gated blood pool method (RVEF(GBP)) under exercise conditions. METHODS AND RESULTS: Twenty-two patients with different cardiac diseases underwent right heart catheterization, including RVEF(TD) and simultaneous RVEF(GBP) determination at rest and during supine bicycle exercise. Linear regression analysis showed a significant correlation between RVEF(TD) and RVEF(GBP) at rest (r = 0.73, p < or = 0.0005) and during exercise (r = 0.74, p < or = 0.0005). A Wilcoxon analysis showed a high probability of agreement of RVEF(TD) and RVEF(GBP) at rest and exercise (level of significance for error of the 0 hypothesis of 95.9/73.3%). CONCLUSION: The thermodilution ejection fraction catheter provides a useful device for reliable, repetitive and safe RVEF measurements, not only at rest but also under exercise conditions. This seems to be clinically important, because by it means RVEF, as a sensitive parameter of primary or secondary right ventricular dysfunction, can be determined in the course of standard right heart catheterization.

Adenosine in the noninvasive diagnosis of dual AV nodal conduction: use as a follow-up parameter after slow pathway ablation in AVNRT.

OBJECTIVE: The aim of this study was to evaluate if administration of adenosine during sinus rhythm to patients with PSVT of unknown mechanism is capable to detect dual AV nodal conduction and furthermore to evaluate this diagnostic parameter as a controlling test after slow pathway ablation in AVNRT. METHODS AND RESULTS: Before electrophysiological study 35 consecutive patients with PSVT were given adenosine during sinus rhythm. After radiofrequency ablation the adenosine test was repeated in a subset of 19 patients. The electrophysiological study revealed 19 patients (54%) with typical AVNRT (study group), 10 (29%) with atrioventricular reentry tachycardia (AVRT), 4 (11%) with ectopic atrial tachycardia (EAT) and 2 patients (6%) with inducible atrial flutter (AF) (control group). We observed a sudden increment of the PQ interval of more than 50 msec between two consecutive beats in 15 of 19 patients (79%) in the study group (75+/-35 msec) and in 2 patients (1 with EAT, AF) of the control group (19+/-12 msec) (p<0.001). After slow pathway radiofrequency ablation the sudden increment of PQ interval persisted in 4 of 12 patients (33%) of the study group. Three of these 4 patients had a relapse of AVNRT during a follow-up of 3 months. CONCLUSION: The administration of adenosine during sinus rhythm is an excellent noninvasive diagnostic test for identifying dual AV nodal conduction and additionally for verifying radiofrequency ablation results in patients with AVNRT.