Andreas Schuchert

Automatic home monitoring of implantable cardioverter defibrillators

AIMS With the expanding indications for implantable cardioverter defibrillator (ICD) and reports of unexpected ICD failures, home monitoring (HM) was proposed to decrease follow-up workload and increase patient safety. Home monitoring implantable cardioverter defibrillators offer wireless, everyday transfer of ICD status and therapy data to a central HM Service Center, which notifies the attending physician of relevant HM events. We evaluated functionality and safety of HM ICDs. METHODS AND RESULTS A total of 260 patients with HM ICDs were monitored for a mean of 10 +/- 5 months. Time to HM events [medical (ventricular tachycardia/ventricular fibrillation) and technical (ICD system integrity)] since ICD implantation and since the latest in-clinic follow-up was analysed. Mean number of HM events per 100 patients per day was calculated, without and with a 2-day blanking period for re-notifying the same type of event. About 41.2% of the patients had HM events (38.1% medical, 0.8% technical, and 2.3% both types). Probability of any HM event after 1.5 years was 0.50 (95% confidence interval: 0.42-0.58). More than 60% of new HM event types occurred within the first month after follow-up. A mean of 0.86 event notifications was received per 100 patients per day or 0.45 with the 2-day blanking period. CONCLUSION Home monitoring is feasible and associated with an early detection of medical and technical events.

Impact of long-term ECG recording on the detection of paroxysmal atrial fibrillation in patients after an acute ischemic stroke.

An ECG recording time of 24 hours has a low yield to detect atrial arrhythmias in patients after an acute ischemic stroke. The present study investigated whether a recording time of 72 instead of 24 hours detects paroxysmal atrial fibrillation in more patients. The study prospectively included 82 consecutive patients 2–3 weeks after an acute ischemic stroke. All patients had sinus rhythm in the resting ECGs and no history of atrial fibrillation or flutter. The frequency of atrial fibrillation was assessed after 24, 48, and 72 hours of ambulatory ECG monitoring. An ECG monitoring time of 72 hours documented paroxysmal atrial fibrillation in five (6%) patients. The episode of paroxysmal atrial fibrillation occurred in only one patient within 24 hours. The other patients had their first episode of atrial fibrillation between 24 and 48 hours (n = 2) and between 48 and 72 hours (n = 2). These five patients were older (age = 70 ± 5 years), whereas the mean age of the remaining patients was 59 ± 13 years. All five patients had cardiovascular disease in comparison to 36 of 77 patients and reported palpitations in comparison to 6 of 77 of the remaining patients. In conclusion, ambulatory ECG monitoring over 72 hours detected after the first recording day four of five patients in whom paroxysmal atrial fibrillation could be documented for the first time. The 72‐hour recording time improved, compared to the 24‐hour period, the detection of paroxysmal atrial fibrillation in patients after an ischemic stroke. It seems to be more efficient to perform prolonged ECG recording mainly in older patients with a cardiovascular disease and/or a history of palpitations.

Prehospital testing for troponin T in patients with suspected acute myocardial infarction

BACKGROUND Cardiac troponin T (TnT) is a highly sensitive and specific marker for myocardial damage and can be detected early after myocardial injury. Our hypothesis was to use TnT as an objective marker to verify acute myocardial infarction before hospital admission. METHODS AND RESULTS We evaluated the sensitivity of a rapid qualitative assay for serum TnT for the detection of acute myocardial infarction in the ambulance and assessed the predictive value of a positive prehospital TnT test for death and myocardial infarction during 6-months of follow-up. The study, conducted in an urban area, included 158 consecutive patients with suspected acute myocardial infarction (93 men aged 69 +/- 13 years). A myocardial infarction was confirmed in 40 and excluded in 118 patients. The prehospital TnT test was positive in 11 patients, of whom 7 had acute myocardial infarction. Fifty-three patients had a positive test result at hospital admission, with evidence of myocardial infarction in 39 of them. The sensitivity to acute myocardial infarction was 18% for the prehospital and 98% for the in-hospital test with 78% and 88% specificity, respectively. During follow-up, patients with a positive prehospital TnT test result had cardiac events more often (9 of 11) than patients with a negative result (26 of 147; P <.0001). CONCLUSIONS In areas with short transport times to the patient the rapid TnT test performed at the point of care identified only a minority of the patients with acute myocardial infarction. A positive prehospital TnT test result seems to be an objective marker for a worse outcome in patients presenting with suspected acute myocardial infarction.

A randomized and controlled pilot trial of beta-blockers for the treatment of recurrent syncope in patients with a positive or negative response to head-up tilt test.

VENTURA, R., et al.: A Randomized and Controlled Pilot Trial of b‐Blockers for the Treatment of Recurrent Syncope in Patients with a Positive or Negative Response to Head‐Up Tilt Test. The aim of this study was to assess the efficacy of lipophilic β‐blockers in preventing recurrent neurocardiogenic syncope and the value of head‐up tilt test (HUT) in predicting response to therapy. The efficacy of β‐blockers in recurrent syncope is controversial. The value of HUT in predicting efficacy of therapy has not been investigated. Fifty‐six patients (44 ± 18 years, 36 women) with recurrent syncope (> 1 event in the last 6 months) of suspected neurocardiogenic origin were included in the study. Independent of the response to HUT, patients were randomized to receive metoprolol or propanolol at the maximal tolerated dose (28 patients, group A, 86 ± 23 vs 98 ± 29 mg/d) or no pharmacological therapy (28 patients, group B). The primary endpoint was the first recurrence of syncope. During the 1‐year of follow‐up, 20 patients of group A and 8 of group B had no recurrence. In group A, of 20 patients without recurrences 12 had a positive and 8 a negative HUT result while of 8 patients with recurrences 5 had a positive and 3 a negative response to HUT. In the group B, of 20 patients with recurrences 10 had a positive and 10 a negative HUT result while of 8 patients without recurrences 4 had a positive and 4 a negative response to HUT. In a multivariate Cox‐regression analysis, medical therapy was the only independent factor for predicting recurrence of syncope (P = 0.004); HUT had no influence in this regard (P = 0.773). In conclusion, lipophilic β‐blockers appear efficacious in preventing recurrent syncope of suspected neurocardiogenic origin. The efficacy of therapy seems to be not predicted by HUT.

Diagnostic yield of external electrocardiographic loop recorders in patients with recurrent syncope and negative tilt table test.

External electrocardiographic loop recording permits extended cardiac rhythm monitoring and ECG storage before and after device activation. The purpose of the study was to assess the diagnostic yield of external loop recorders in patients with more than two syncopal events within the last 6 months and a negative tilt table test. Twenty‐four consecutive patients (51 ± 14 years, male n = 9) were enrolled with 3 ± 4 recurrent syncopal events within the last 6 months and no overt structural heart disease. The loop recorder CardioCall continuously records a two‐channel ECG via skin electrodes. When activated, up to 4.5 minutes of the ECG preceding activation is stored. The time between tilt table testing and monitoring was 5 ± 4 weeks. The average monitoring period covered 50 ± 22 days. Recording was either unsuccessful or terminated prematurely in 5 patients. The reasons were skin irritation secondary to the electrodes in two patients, cable damage in one patient, and two patients inadvertently erased the stored data when replacing the batteries. Fourteen patients activated the loop recorder at least once. Symptoms leading to device activation were syncope (n = 1), dizziness (n = 11), feeling unwell (n = 7), palpitations (n = 5), headaches (n = 1), and chest pain (n = 1). The loop recorder documented sinus tachycardia during the syncopal event. Sinus tachycardia was also observed in 7 other patients, and atrial flutter in two patients. Eight patients had recurrent syncope with two patients experiencing syncope prior to the monitoring period, one syncope occurred in a patient who inadvertently erased the stored data, one event coincided with sinus tachycardia, and 4 (17%) patients had syncope during 15 ± 10 months after termination of loop monitoring. The external loop recorder was not very useful for arrhythmia detection in patients with syncopal events, no overt heart disease, and a negative tilt table test because the cardiac rhythm was stored in only 1 of 8 (13%) patients with recurrent syncope. Reasons for the low diagnostic yield of external loop recorders were infrequent syncopal events after the baseline evaluation, with rare events during the limited monitoring period in particular, and premature termination or unsuccessful recording in 21% of patients. (PACE 2003; 26:1837–1840)

Lead complications, device infections, and clinical outcomes in the first year after implantation of cardiac resynchronization therapy-defibrillator and cardiac resynchronization therapy-pacemaker

AIMS The decision to implant a cardiac resynchronization therapy (CRT) system with (defibrillator, CRT-D) or without (pacemaker, CRT-P) cardioverter defibrillator should weigh its benefits and risks. This study examined the (i) incidence of loss of capture and infectious complications and (ii) 1-year clinical outcomes of 402 CRT-D and CRT-P recipients enrolled in the MASCOT study. METHODS AND RESULTS The indications for CRT-D or CRT-P were posed by the implanting physicians. All (i) losses of atrial and right and left ventricular capture, (ii) system-related infections, and (iii) clinical outcomes, including hospitalizations for worsening heart failure (HF) and deaths from all causes, were recorded up to 1 year of follow-up. Cardiac resynchronization therapy-defibrillator was implanted in 228 (57%) and CRT-P in 174 (43%) patients. The incidence of loss of capture was greater in CRT-D with 21 patients (9.2%) than in CRT-P with 6 patient (3.5%) recipients (P = 0.01), while the infection rates were 1.3% (3 patients) and 1.2% (2 patients), respectively (ns). In the CRT-D group, 42 of 228 patients (18.4%) died or were hospitalized for HF, compared with 38 of 174 patients (21.8%) in the CRT-P group (ns). In the CRT-D group, 23 patients (10.1%) were hospitalized for worsening HF and 20 (8.8%) patients died, vs. 22 (12.6%) and 19 (10.9%) patients, respectively, in the CRT-P group (ns for both comparisons). CONCLUSIONS Cardiac resynchronization therapy-defibrillator was implanted in 57% of candidates for CRT. Within 1 year after device implant, the incidence of loss of capture at any lead was nearly three-fold greater among CRT-D than among CRT-P recipients. System-related infections were infrequent and clinical outcomes were similar in both groups.

A Prospective Randomized Evaluation of VV Delay Optimization in CRT‐D Recipients: Echocardiographic Observations from the RHYTHM II ICD Study

Background: All current cardiac resynchronization therapy (CRT) devices allow the programming of the atrioventricular (AV/PV) delays and the sequential stimulation of the ventricles via the inter ventricular (VV) delay.

Kommentar zu den Leitlinien zur Diagnostik und Therapie von Synkopen - : der Europäischen Gesellschaft für Kardiologie 2001 und dem Update 2004

Priv.-Doz. Dr. Karlheinz Seidl ()) Herzzentrum Ludwigshafen Medizinische Klinik B (Kardiologie, Pneumologie, Angiologie) Bremserstr. 79 67063 Ludwigshafen, Germany Tel.: 0621/503 40 18 Fax: 0621/503 40 28 E-Mail: seidlk@klilu.de Prof. Dr. Andreas Schuchert Medizinische Klinik III Universitätsklinikum Hamburg-Eppendorf Martinistr. 52 20246 Hamburg, Germany Tel.: 040/42803-53 04 Fax: 040/42803-57 66 E-Mail: schuchert@uke.uni-hamburg.de

Home telemonitoring in patients with chronic heart failure: a chance to improve patient care?

BACKGROUND Telemonitoring can improve the medical care, quality of life, and prognosis of chronically ill patients. This review article summarizes the current status of health services research on telemonitoring, focusing on patients with chronic congestive heart failure. METHOD The Medline database was selectively searched for articles appearing from June 2001 to May 2008, with an emphasis on randomized, controlled trials. RESULTS The available scientific data on vital signs monitoring are limited, yet there is evidence for a positive effect on some clinical endpoints, particularly mortality. Nonetheless, any possible improvement of patient-reported outcomes, such as the quality of life, still remains to be demonstrated. CONCLUSIONS The data suggest that telemonitoring is effective, yet there is no evidence for superior outcomes with any particular model of care incorporating telemonitoring (i.e., monitoring of vital signs versus structured telephone monitoring). A valid criticism is that the individual components of home telemonitoring have not yet been separately tested in order to compare their individual effects.

Two-Year Performance of a Preshaped Lead for Left Ventricular Stimulation

Important goals, when implanting a cardiac resynchronization therapy (CRT) system, are to reach a stable LV lead position in a suitable coronary sinus (CS) tributary associated with a low capture threshold and no extracardiac stimulation. The aim of this study was to assess the 2‐year performance of a new preshaped lead designed for LV stimulation. The study enrolled 102 patients with heart failure and bundle branch block who underwent implantation of a CRT system, including a sheath‐guided, unipolar, S‐shaped LV lead placed in a CS tributary. At each follow‐up the electrical parameters and CRT system related adverse events were recorded. Eight patients who underwent LV stimulation alone, versus 88 patients who received biventricular CRT systems, were analyzed separately. Access to the CS was reached in 98 patients, and the lead was permanently implanted in 96 (94%) patients. The overall procedural time was 98 ± 28 minutes. During follow‐up, three patients underwent reinterventions for phrenic nerve stimulation (n = 2) and hematoma (n = 1). The capture threshold at implantation was 1.4 ± 0.9 V with LV versus 1.7 ± 0.5 V with biventricular stimulation, and after a transient increase, remained between 1.6 and 1.9 V in both configurations. The device measured impedance was significantly higher with LV than with biventricular stimulation at the time of CRT system implantation (698 ± 296 Ω vs 380 ± 67 Ω, P < 0.05) and during follow‐up. The initial R wave amplitude was 14.3 ± 5.9 mV in LV versus 8.9 ± 3.2 V in the biventricular configuration (NS) and 13.8 ± 7 mV in LV versus 12.8 ± 4.8 mV in the biventricular configuration at 24 months (NS). Implantation of the S‐shaped LV lead for CRT was safe, expeditious, and associated with a high success rate and reliable long‐term performance.