Gerhard Stark

Effect of Home-Based Telemonitoring Using Mobile Phone Technology on the Outcome of Heart Failure Patients After an Episode of Acute Decompensation: Randomized Controlled Trial

Background Telemonitoring of patients with chronic heart failure (CHF) is an emerging concept to detect early warning signs of impending acute decompensation in order to prevent hospitalization. Objective The goal of the MOBIle TELemonitoring in Heart Failure Patients Study (MOBITEL) was to evaluate the impact of home-based telemonitoring using Internet and mobile phone technology on the outcome of heart failure patients after an episode of acute decompensation. Methods Patients were randomly allocated to pharmacological treatment (control group) or to pharmacological treatment with telemedical surveillance for 6 months (tele group). Patients randomized into the tele group were equipped with mobile phone–based patient terminals for data acquisition and data transmission to the monitoring center. Study physicians had continuous access to the data via a secure Web portal. If transmitted values went outside individually adjustable borders, study physicians were sent an email alert. Primary endpoint was hospitalization for worsening CHF or death from cardiovascular cause. Results The study was stopped after randomization of 120 patients (85 male, 35 female); median age was 66 years (IQR 62-72). The control group comprised 54 patients (39 male, 15 female) with a median age of 67 years (IQR 61-72), and the tele group included 54 patients (40 male, 14 female) with a median age of 65 years (IQR 62-72). There was no significant difference between groups with regard to baseline characteristics. Twelve tele group patients were unable to begin data transmission due to the inability of these patients to properly operate the mobile phone (“never beginners”). Four patients did not finish the study due to personal reasons. Intention-to-treat analysis at study end indicated that 18 control group patients (33%) reached the primary endpoint (1 death, 17 hospitalizations), compared with 11 tele group patients (17%, 0 deaths, 11 hospitalizations; relative risk reduction 50%, 95% CI 3-74%, P = .06). Per-protocol analysis revealed that 15% of tele group patients (0 deaths, 8 hospitalizations) reached the primary endpoint (relative risk reduction 54%, 95% CI 7-79%, P= .04). NYHA class improved by one class in tele group patients only (P< .001). Tele group patients who were hospitalized for worsening heart failure during the study had a significantly shorter length of stay (median 6.5 days, IQR 5.5-8.3) compared with control group patients (median 10.0 days, IQR 7.0-13.0; P= .04). The event rate of never beginners was not higher than the event rate of control group patients. Conclusions Telemonitoring using mobile phones as patient terminals has the potential to reduce frequency and duration of heart failure hospitalizations. Providing elderly patients with an adequate user interface for daily data acquisition remains a challenging component of such a concept.

The Outback Catheter: A New Device for True Lumen Re-entry After Dissection During Recanalization of Arterial Occlusions

Abstract To report the initial experience with a new catheter system (The Outback catheter) designed to allow fluoroscopically controlled re-entry of the true arterial lumen after subintimal guidewire passage during recanalization procedures of arterial occlusions. The catheter was used in 10 patients with intermittent claudication caused by chronic segmental occlusions of the superficial femoral or popliteal arteries. In all patients, conventional guidewire recanalization had failed. In 8 patients, successful true lumen re-entry was achieved with the Outback catheter. Percutaneous transluminal angioplasty was successfully performed in these patients without complications. Two technical failures occurred in heavily calcified arteries. The Outback catheter was safe and effective when used in complicated recanalization procedures in the superficial femoral and popliteal artery and the tibial trunk.

Cystic adventitial degeneration of the popliteal artery — the diagnostic value of duplex sonography

Cystical adventitial degeneration of the popliteal artery is a disorder which is difficult to diagnose, due to the similarity of the symptoms of people presenting with peripheral arterial occlusive disease (PAOD) or popliteal entrapment syndrome. The only thing that differs from patients suffering from PAOD is the lack of typical risk factors for arteriosclerosis. Typical diagnostic procedures like conventional angiography or magnetic resonance Imaging angiography can be negative, too and therefore misleading. The only which is crucial in the diagnosis of cystic adventitial degeneration of the popliteal artery is to know the morphological background of this disorder, namely that it is a cyst of the adventitia of the artery which leads to a dynamic exercise-dependent flow inhibition. We present a 57-year old white male who had a weeks history of intermittent claudication in his left calf. He was lacking of typical risk factors for arteriosclerosis and on first examination all pulses in both lower extremities were palpable and Doppler index on both legs was >1. Only duplexsonography revealed a cystic formation impressing the left popliteal artery in the hight of the rift in the popliteal joint.

Pulsed excimer laser versus continuous-wave Nd:YAG laser versus conventional angioplasty of peripheral arterial occlusions: prospective, controlled, randomised trial

Early clinical studies of coronary and peripheral laser angioplasty showed that arterial occlusions could be recanalised by continuous-wave lasers delivered with contact probes and by pulsed lasers applied with multifibre catheters. However, whether laser-assisted angioplasty improves success rates in reopening occlusions and in long-term patency rates is unclear. We have compared the primary recanalisation and long-term patency rates after laser-assisted and conventional percutaneous transluminal angioplasty (PTA) of femoropopliteal artery occlusions in 116 consecutive symptomatic patients (excimer laser 37, Nd:YAG laser 40, PTA 39). Primary recanalisation was achieved in 81 patients (70%). The primary recanalisation rate achieved with the excimer laser was significantly lower than that with the Nd:YAG laser (49% vs 78%, p < 0.01) or with PTA (82%, p < 0.003). The overall angiographic recanalisation rate (primary and secondary recanalisation) after laser and PTA was 89%. After 3 months, clinical improvement was recorded in 76% of patients. Clinical long-term results were available in 94 (91%), and angiographic long-term results in 77 (75%), of 103 successfully recanalised patients. Life-table analysis of the long-term results revealed no significant difference of the restenosis rate between the three treatment groups. The 12-month patency rate was 60% as assessed clinically and 39% as judged by angiography. Primary and secondary recanalisation rates and long-term patency rates were significantly correlated with length of the occlusion. Our results suggest that PTA of femoropopliteal artery occlusions is only indicated if the occlusion is short (< 8 cm) and that laser-assisted angioplasty should only be used after failure of conventional PTA.

Different stereoselective effects of (R)- and (S)-propafenone : clinical pharmacologic, electrophysiologic, and radioligand binding studies

Propafenone is a class 1c antiarrhythmic agent with moderate β‐blocking activity as a result of a structural similarity to β‐adrenoceptor antagonists. In a randomized, double‐blind crossover exercise study, eight healthy volunteers were examined before and 2½ hours after oral administration of 300 mg (R,S)‐, 150 mg (R)‐, and 150 mg (S)‐propafenone hydrochloride. The mean rate pressure product was significantly reduced by (R,S)‐propafenone hydrochloride (− 5.2%; p = 0.045) and half‐dosed (S)‐propafenone hydrochloride (−5.9%; p = 0.013), whereas the (R)‐enantiomer caused no significant changes. There was a significant difference between the effects of (R)‐ and (S)‐propafenone (p = 0.033). In β‐adrenoceptor–binding inhibition experiments with (S)‐(125I)iodocyanopindolol in a sarcolemmaenriched cardiac membrane preparation, the eudismic ratio of (S)‐ over (R)‐propafenone was 54. On the spontaneously beating Langendorff‐perfused guinea pig heart, 3 · 10−6 mol/L of both (R)‐ and (S)‐propafenone resulted in significant changes (p < 0.01) on His bundle conduction (+ 79% ± 27% and + 69% ± 9%), as well as comparable decreases in the maximal rate of pacing with 1:1 conduction of the atrial (−54% ± 10% and −57% ± 8%) and ventricular myocardium (−42% ± 6% and −43% ± 6%), indicating equal effects in sodium channel–dependent antiarrhythmic class 1 activity. Thus (R)‐ and (S)‐propafenone exert different β‐blocking actions but equal effects on the sodium channel–dependent antiarrhythmic class 1 activity. More specific antiarrhythmic class 1 therapy with reduction of β‐blocking side effects may be attained with optically pure (R)‐propafenone hydrochloride instead of the currently used racemic mixture.

Assessment of the conduction of the cardiac impulse by a new epicardiac surface and stimulation technique (SST-ECG) in Langendorff perfused mammalian hearts.

The assessment of the effects on the conduction of the cardiac impulse and of refractoriness simultaneously from multiple cardiac structures is important to evaluate the mode of action of new compounds, as well as to investigate undesired cardiac side effects. The measurements of intracardiac electrical activities of special structures have required catheter methods or averaging techniques to produce clear deflections of low-level potential wave forms. We have developed an epicardial surface electrocardiogram (S-ECG) recording technique to detect continuously sinus node and His-bundle activities in spontaneously beating Langendorff perfused heart preparations. A bipolar surface stimulation technique electrocardiogram (ST-ECG) could be combined with this S-ECG method to assess the effect of pacing at maximal rate on the refractoriness of the sino-atrial, AV-nodal, and His-bundle conduction, as well as that of the atrial and ventricular myocardium. Epicardial surface electrodes were also used for vector analysis of the signals, which include those of the sinus node and His-bundle potentials, in addition to the usual atrial and ventricular loops. The present results demonstrate that this new epicardial surface ECG recording technique, combined with the described SST-ECG, provided a way to improve or replace more elaborate intracardiac techniques used in isolated hearts or in animal experiments.

A prospective evaluation of sensitivity and specificity of the ankle/brachial index in the follow-up of superficial femoral artery occlusions treated by angioplasty.

The aim of this study was to provide estimates of sensitivity and specificity of clinical history, pulses, and ankle/brachial index (ABI) in the follow-up of atherosclerotic occlusions of the superficial femoral artery treated by peripheral transluminal angioplasty (PTA). A total of 116 patients were followed prospectively for 1 year after angioplasty with follow-up visits immediately after angioplasty, and at 3, 6, and 12 months. All patients underwent digital subtraction angiography after 1 year or if they reported a deterioration of their symptoms. Reobstruction was defined as reocclusion or as restenosis exceeding 70%. Patency rates were calculated separately by clinical and ankle/ brachial criteria; sensitivity and specificity were derived using angiography as standard. The presence or absence of pulses distal to the treated vessel segment had a sensitivity of 78% and a specificity of 66% for a reocclusion or significant restenosis; subjective complaints evaluated by history had a sensitivity of 83% and a specificity of 51%. The sensitivity of the ABI was 72% and 66%, with a specificity of 82% and 100% for cutoff values of 0.10 and 0.15, respectively. One year after PTA the angiographic patency rate was 39 % ± 5 %; the patency rate based on ABI criteria 34% ± 5%. A deterioration in the ABI by 0.15 indicated with reasonable certainty a reocclusion or significant restenosis whereas the sensitivity of the ABI was poor in detecting significant restenosis after PTA of occlusions of the superficial femoral artery. When only clinical criteria were used, the true patency rate was significantly overestimated as more than half of all reobstructions remained asymptomatic.

Modulation of cardiac impulse generation and conduction by nifedipine and verapamil analyzed by a refined surface ECG technique in Langendorff perfused guinea pig hearts

SummaryUsing a modified Langendorff system, a special ECG recording technique and appropriate placement of two silver wire electrodes, early atrial and His bundle activity can be detected continuously from the surface of intact and spontaneously beating guinea pig hearts. This new method was applied to measure the direct and inhibitory effects of nifedipine and verapamil on impulse generation and conduction in isolated and perfused guinea pig hearts. Depression of sinoatrial conduction was the most prominent effect of nifedipine. In all concentrations applied (10−7 M, 10−6 M, 10−5 M) nifedipine predominantly led to sinoatrial blocks of different degrees. Heart rate decreased slightly in a dosedependent manner. PQ and HV duration remained essentially constant. In the highest concentration of nifedipine (10−5 M), sinus node activity was so depressed that AV dissociation or ventricular rhythm developed. Only in one out of eight experiments with cumulative increase of nifedipine concentrations to 10−5 M was the AV node affected by nifedipine and a second-degree AV block developed (10−6 M).Verapamils inhibitory effects on the rate of impulse initiation in the sinus node were more pronounced than those of nifedipine, but the inhibition of sinoatrial conduction by verapamil was less marked. At 10−6 M verapamil, the incidence of sinoatrial blocks and of ventricular rhythm was similar to the incidence of first degree AV blocks. PQ time (+14%) but also HV time (+12%) were prolonged under the influence of this concentration of verapamil. At the highest concentration of verapamil (10−5 M) applied for 10 min, ventricular rhythm developed in five out of eight experiments, as well as one second and two third-degree AV blocks.The results confirm that the simultaneous measurement of sinus node activity of sinoatrial and atrioventricular conduction and of HV duration is feasible with this ECG technique, to evaluate the inhibitory effects of Ca-antagonists on sinus and AV node activity in the intact heart.

Prothrombotic Risk Factors in Patients with Thrombangitis Obliterans

XIII Histological findings in arteries of patients with TAO show that the segmental inflammatory process in the vessel wall is accompanied by a thromSince its first description in 1908 by Leo botic occlusion in the arteries. Therefore, the purBuerger, not very much has changed about pose of our study was to evaluate if prothrombotic the principal insight into the pathogenesis, risk factors can be found in patients suffering from diagnosis and treatment of thrombangitis obliterTAO at a higher level than in a control group ans (TAO) or Buergeŕs disease [1–11]. It is defined lacking venous or arterial disease. From the clinical as a segmental inflammatory occlusive disease point of view, the thrombotic occlusion might be which primarily affects small or medium-sized arthe reason for the worsening of the chronic course teries and veins in the extremities of young of the disease. The pathomechanism for the occuradults [1]. rence of the thrombotic occlusion is unclear. It Characteristically TAO begins relatively early in might be either the inflammatory process of the life, usually between the ages of 25 and 35, and is vessel wall itself or might be caused by a hypercoamore common in men than women with a prevagulable state enhanced by prothrombotic risk lence up to 10:1. There is an intimate relationship factors. between smoking and TAO. Typically all other risk factors for peripheral arterial occlusive disease 1. Patients and Methods (PAOD) like hypercholesterinemia, hypertension or diabetes mellitus are lacking at the time of diag1.1. Patients nosis [3]. Concerning other risk factors or predisposing Twenty-eight patients (17 male and 11 female) with factors, only a few are found in the literature [4–7]. a history of TAO were enrolled in our study. The These papers show a possible relationship of an mean age was 43.8 6 8.8 years. They were diagMHC Class I chain-related gene A (MICA) polynosed with TAO between 1990 and 1998. At the time of diagnosis all of them had been smoking heavily and the diagnosis of TAO was made acAbbreviations: Thrombangitis obliterans, TAO; MHC Class I cording to the following clinical criteria: onset bechain-related gene A, MICA; polymorphism, MICA 1.4; peripheral arterial occlusive disease, PAOD. fore the age of 50, history of smoking, absence Corresponding author: Dr. Marianne Brodmann, Division of Anof arteriosclerotic risk factors other than smoking, giology, Department of Internal Medicine, Karl Franzens Univerinfrapopliteal arterial occlusive lesions, and either sity, Graz A-8036, Graz, Austria. Tel:143 (316) 385 2911; Fax: 143 (316) 385 3788; E-mail: ,marianne.brodmann@kfunigraz.ac.at.. upper-limb involvement or phlebitis migrans.

Continuous ECG measurements of intracardiac activity from the surface of Langendorff-perfused guinea pig hearts

SummaryThe present paper describes a method by which it is possible to continuously detect early atrial and His-bundle activity from the surface of intact Langendorff-perfused guinea-pig hearts, by appropriate placement of two electrodes and the use of a custom designed instrumentation-amplifier. In some experiments the surface ECG recordings were compared with intracardiac ECG recordings. No difference in ECG durations could be observed between intracardiac and extracardiac measurements. In further experiments changes in ECG durations and heart rate were measured for 2 h. After 30 min equilibration time, no changes in heart rate and conduction time could be observed. In order to locate the best surface electrode positions to detect His-bundle activity, vector ECG recordings were taken at high gain. This vector ECG signal contained a His-loop which was split into a larger and a smaller part. The main and initial vector was directed to the left and the smaller to the right ventricle. The best recordings of the His-bundle activity could be observed when the electrodes were positioned as follows; one in a posterior position, near the valve plane and the other one in the opposite position near the initial part of the anterior interventricular artery and in the direction of the large His-loop.We conclude that the ECG surface recordings are a valuable tool for measuring impulse propagation through various segments of the cardiac conduction system in preparations of guinea-pig hearts, perfused by the Langendorff method.