Implantation of left ventricular epicardial leads in cardiosurgical patients with impaired cardiac function--a worthwhile procedure in concomitant surgical interventions?

BACKGROUND: Cardiac resynchronization therapy (CRT) by means of multisite biventricular pacing is an effective therapeutic option for the treatment of severe heart failure. The present study estimates how many open heart-surgery patients could benefit from the implantation of permanent left ventricular (LV) pacing leads. After routine preoperative screening, epicardial electrodes were implanted in selected patients. Lead performance and outcomes were investigated. METHODS: Primarily, 1059 patients were retrospectively investigated with regard to LV function, left bundle branch block and QRS duration. Afterwards, suitable patients were identified and epicardial electrodes [Medtronic 5071 (ME) or Enpath (EP)] were implanted during concomitant procedures. Mean follow-up time was 6.3 ± 5.5 months. RESULTS: The retrospective study showed that 24 patients (2.3%) could potentially profit from CRT. After routine preoperative screening for CRT-responders, 22 patients (1.6%) were identified who finally received epicardial leads. No complications occurred. Acute capture threshold was 0.9 ± 0.4 V (ME, n = 17) and 0.5 ± 0.2 V (EP, n = 5). While leads in 18 patients were implanted as an upgrade to an existing pacemaker or implantable cardioverter-defibrillator (ICD) technologies (Group B), 4 patients underwent prophylactic implantation with no device attached (Group A). CRT-ICDs were implanted at follow-up in 3 Group A patients (75%). In Group B patients, the QRS duration decreased (from 189 ± 35 ms to 152 ± 16 ms, p < 0.02) and their postoperative mean NYHA functional class improved significantly (2.2 ± 0.5 versus 2.8 ± 0.6). CONCLUSION: A small group of cardiac surgery patients may benefit from LV-lead implantation during concomitant procedures. A protocol for responder identification is useful. Existing devices should be upgraded to CRT systems. As CRT-ICD implantation is frequent, the additional costs and time are justified.

[Traumatic tricuspid valve insufficiency with right-to-left shunt: bridging using extracorporeal venovenous membrane oxygenation]. / Traumatische Trikuspidalklappeninsuffizienz mit Rechts-links-Shunt: "Bridging" mithilfe der extrakorporalen venovenösen Membranoxygenierung.

The case of a young male motor vehicle driver is reported who suffered multiple trauma in a car accident with pulmonary and cardiac contusions. In the course of severe pneumonia and traumatic tricuspid valve insufficiency a right-to-left shunt with refractory hypoxemia developed across a pre-existing atrial septal defect (ASD). The patient could be successfully treated by the combination of extracorporeal membrane oxygenation for bridging, interventional ASD occlusion and in the long-term by operative reconstruction of the tricuspid valve.

[Medical technology and medical education]. / Medizintechnik in der ärztlichen Aus-, Weiter- und Fortbildung.

The education of medical professionals is divided into medical studies, postgraduate training leading to the qualification as a specialist, and continuing professional development. During education, all scientific knowledge and practical skills are to be acquired, which enable the physician to practice responsibly in a specialized medical area. In the present article, relevant curricula are analyzed regarding the consideration of medical device-related topics, as the clinical application of medical technology has reached a central position in modern patient care. Due to the enormous scientific and technical progress, this area has become as important as pharmacotherapy. Our evaluation shows that medical device-related topics are currently underrepresented in the course of medical education and training and should be given greater consideration in all areas of medical education. Possible solutions are presented.

[Medical devices and patient safety from the clinicians' view]. / Medizinprodukte und Patientensicherheit aus der Perspektive des Klinikers.

In daily routine, clinically orientated physicians are confronted with various, often highly sophisticated medical devices. To ensure safe handling and usage, licensees and operators of those devices have to follow regulations and laws given by the German medical device legislation. For the clinician as an active user of the technology, basic knowledge of these regulations is essential. Quality-based health care focuses on the important issue of patient safety. Medical devices have made their way into virtually every sector of patient care. However, despite usage of these devices bearing substantial risk of adverse events, the problem of safe handling of sophisticated technology plays only a minor part in medical academic studies, medical specialist training, and manda nottory continuing education of physicians. The option of further education is needed to ensure patient safety and protect operators of medical devices.

[Incidents of malfunction of mechanical heart valves as reported to the German Medical Devices Vigilance System]. / Vorkommnismeldungen bei mechanischen Herzklappenprothesen. Auswertung des deutschen Medizinprodukte-Beobachtungs- und Meldesystems im Bundesinstitut für Arzneimittel und Medizinprodukte.

BACKGROUND: The purpose of this study was to collect the experience gained from risk assessment of incidents associated with mechanical heart valves as reported to the German Medical Devices Vigilance System. METHODS: All events in connection with the use of prosthetic heart valves which had been reported to the Federal Institute for Drugs and Medical Products were identified in the Institute's anonymized database. Subsequently all information that had been obtained and the reports of investigations by the various responsible manufacturer of medical products were retrospectively analysed. RESULTS: Of 53 incident reports the aortic valve position was involved 32 times, the mitral valve position 21 times. 17 cases of leaflet breakage, 12 of leaflet dysfunction, 6 of valve thrombosis, 4 of paravalvular leakage, 4 of damage to the suture ring, 3 of endocarditis and 7 of various other singular defects were reported. The outcome was mostly very serious (re-surgery, prolongation of surgery, death). Corrective actions taken by the manufacturers consisted of recalls, advisory notices and stoppage of production. CONCLUSIONS: The Medical Devices Vigilance System is able to detect product failures of mechanical heart valves and to initiate corrective action. As the reporting rate over more than 10 years is relatively low, it can be assumed that in general mechanical heart valves are safe medical devices. The quality of incident reporting by manufactures and users of medical devices should be improved to reduce the number of undetected and unsolved incidents.

Therapeutic optimization of atrioventricular delay in cardiosurgical ICU patients by noninvasive cardiac output measurements versus pulse contour analysis.

BACKGROUND: Optimizing atrioventricular (AV) delay improves cardiac output and postoperative outcome. Impedance cardiography (ICG) is a non-invasive method for CO measurement. This study evaluates the ability of two ICG methods to determine the optimal AV delay (OAVD) and to compare ICG with invasive PICCO measurements. METHODS: In 14 cardiosurgical ICU patients (age 70.4 +/- 12.0 yrs) with temporary pacing wires, OAVD was determined by pulse contour analysis (PICCO) and ICG (conventional ICG [CI] and electrical velocimetry [EV] ICG monitors). Cardiac output (CO) and stroke volume (SV) were measured during DDD pacing with AVD varying from 70 to 270 ms in 20-ms increments. RESULTS: Measured OAV showed a linear correlation between PICCO and ICG: CI (r = 0.82, P < 0.0002) and EV (r = 0.84, P < 0.0002). The mean OAVD deviation between PICCO and ICG was 15.7 +/- 21.0 ms (CI) and 17.1 +/- 20.5 ms (EV). Hemodynamic parameters (SV increase OAVD against worst case) improved significantly (+ 11.7 +/- 7.2 %, P < 0.0001). CONCLUSION: Inappropriate selection of AVD can compromise the hemodynamic situation of cardiosurgical patients. As it is totally noninvasive, ICG is a reliable and effective tool for tailoring AVD. Both systems (CI and EV) offer valid OAV determination.

Surgical management of complications caused by transcatheter ASD closure.

BACKGROUND: Transcatheter occlusion of uncomplicated atrial septum defects (ASD) is recognized as an effective and minimally invasive method. Sometimes, serious early and late complications require surgical intervention. We therefore investigated reasons and outcomes of the secondary surgical approach. METHODS: 5 patients (aged 5-73 yrs) were admitted to our institution for device explantation and surgical ASD closure. ASDOS devices (A devices) had to be explanted in 4 patients and a SIDERIS "buttoned" occluder (S device) had to be explanted in 1 patient. The period from transcatheter implantation to surgical explantation ranged from 1 hour to 3 years. RESULTS: 3 patients (60 %) had to be operated in an emergency setting. In our youngest patient (5 yrs), the A device separated and embolized into the aorta and pulmonary artery. A pregnant women who needed emergent cesarean section developed hemopericard and tamponade due to atrial perforation by a fractured leg of an A device. In another A device, a suspect endocarditis caused membrane perforation. Malpositioning of an S device was the reason for operation. All patients recovered well without neurological symptoms. CONCLUSIONS: Transcatheter closure of uncomplicated ASD is a feasible alternative but surgical stand-by is essential. Nevertheless more complicated ASD should be operated, especially since the cosmetically satisfactory techniques of minimal invasive heart surgery are available.