[Home monitoring of patients after prosthetic valve replacement-a new method of early detection of valve dysfunction]. / Postoperative Betreuung von Patienten nach alloprothetischem Herzklappenersatz. Neue Methoden zur Risikosenkung sowie Früherkennung von Prothesendysfunktionen.

Despite enormous progress concerning material and design, patients with artificial heart valves still face a considerable risk of serious complications (e. g. hemorrhage, thromboemboli, redos) which sum up to 5-20% within the first 10 postoperative years depending on type and position of the implanted prosthetic valve. Nowadays technical defects of mechanical valves are negligible and relevant complications are most frequently the consequence of inappropriate oral anticoagulation therapy. To avoid these complications a strict control of both the anticoagulation therapy and the functional integrity of the prosthetic valve is mandatory. Therefore with the aim of risk minimization the patient should be enabled to cooperate by means of methods which are easy to handle in his everyday environment. We present a reliable method for early detection of prosthetic valve dysfunction which can be applied daily with minimal effort by the patient himself.

Home monitoring of patients after prosthetic valve surgery -- experimental background and first clinical attempts.

PURPOSE: The purpose of this study was to investigate whether: 1. sound phenomena may be used to detect prosthetic valve dysfunction; 2. clinical and experimental data permit conclusions about alterations in the functional state of mechanical valves; 3. patients can record and pass on signals via Internet. METHODS: 1. We implanted bi-leaflet valves in pigs. By gradually influencing the motion of the tilting discs prosthetic dysfunction could be generated. 2. Thrombosis and lysis of bi-leaflet valves was studied in sheep. This process was documented using echocardiography and acoustically by the Fast Fourier Transformation. 3. Thirty devices were set up and handed out to patients following mechanical valve replacement. All patients regularly sent data to the hospital via Internet, regardless of their location at the time. The data were evaluated by comparing them with the reference file. RESULTS: Animal experiments proved that changes in prosthetic function led to a significant change in sound phenomena. In contrast to echocardiography alterations at an early stage (onset of thrombosis) could be reliably verified. The sensitivity was greater than in echo-control analysis. All patients regularly recorded and passed on their signals. Surveys revealed high acceptance and easy handling of the devices. CONCLUSIONS: Online registration of sound phenomena seems to be suitable for the detection of changes in prosthetic function. This led to the development of the first hand-held device for home monitoring of valve function. Registration of flow, frequency spectrum, and ECG envisaged at the next level opens up potential applications for Internet-based, remote monitoring of cardiac patients.

Surgical repair of pulmonary stenosis with intact ventricular septum in a 68-year-old woman.

Patients with mild pulmonary stenosis after infancy rarely have symptoms or develop increasing obstruction. We experienced a 68-year-old woman with severe pulmonary valvar and infundibular stenosis (peak to peak pressure gradient = 80 mmHg). She had been pointed out heart disease at the age of six. Endocarditis at the age of 17 might induce calcification of valve and affect the progression of pulmonary stenosis, and moreover, which might gradually develop severe subvalvar obstruction and poststenotic aneurysm of pulmonary trunk. She refused operative intervention because of mild clinical symptoms (NYHA class II), but we recommended surgical repair due to repeated transient ischemic attacks, which were suspected paradoxical embolism through persistent foramen ovale. She underwent pulmonary valvotomy and infundibular resection and is doing well.