Biomedical subjects

G Agelopoulos

Publications and source records attributed to G Agelopoulos.

3 recordsLinked to original sources

PubMed2001

In-vivo testing of digital cellular telephones in patients with implantable cardioverter-defibrillators.

AIMS: To investigate the susceptibility of implantable cardioverter defibrillators to electromagnetic interference generated by digital cellular telephones, functioning in both international transmission technologies: the Global System for Mobile Communication (GSM) and the Digital Cellular System (DCS 1800). METHODS AND RESULTS: In 36 patients with transvenous implantable cardioverter defibrillators from two manufacturers (Medtronic and Guidant/CPI), cellular telephones with different levels of minimal and maximal power output were tested in the transmitting and receiving mode. Evaluation was performed in activated implantable defibrillators during spontaneous cardiac activity and continuous VVI or DDD pacing to assess possible electromagnetic interference. In two patients, appropriateness of ventricular fibrillation detection and therapy was judged during telephone testing. There was no damage, reprogramming, inappropriate shock therapy or pacing inhibition during the tests. In seven pre-pectoral Medtronic implantable defibrillators, transient electromagnetic interference caused 19 erroneous sensing events, when the operating phone was held in close vicinity to the programmer head. These 'pseudo-oversensing' events, which did not result in logging of arrhythmia episodes in the device counter, were interpreted as an adverse interaction between the telephone and the programming device. CONCLUSION: Digital cellular telephones do not represent a risk to Medtronic and Guidant/CPI recipients of the specific implantable defibrillator models herein tested.

Defibrillators, Implantable↗

PubMed2001

Initial experience with a newer generation coronary stent.

BACKGROUND: Recently, several newer generation stents have become available promising to improve upon the results of coronary angioplasty (PTCA) with its attendant acute and chronic complications. The aim of this study was to prospectively review the results of a preliminary experience with the newer generation R stent in a series of 56 patients. METHODS: This study included 47 men and 9 women, aged 57 +/- 10 years, who presented with stable angina and/or positive exercise testing (n = 12), unstable angina (n = 42), or acute myocardial infarction (n = 2). A consistent approach by a single operator for implantation of the R stent (Orbus Inc., The Netherlands) included stent oversizing (by 0.5 mm) and high pressure (> 12--16 bar) deployment. Dilated vessels comprised the left anterior descending (n = 37) including the diagonal branch in 2 patients, the right coronary artery (n = 17), the left circumflex (n = 13), or a saphenous vein graft (n = 1). The mean left ventricular ejection fraction was 52 +/- 8% and the initial coronary artery stenosis was 85 +/- 8%. Stents were implanted for dissection and/or suboptimal PTCA result or electively. RESULTS: The procedure was successful in all 56 patients (100%). The residual stenosis was < 0--10%. Direct stenting without balloon predilation was performed in 21 patients. Single stents were used in 36 patients and > or = 2 stents in 20 patients. Abciximab (n = 22), eptifibatide (n = 8) or tirofiban (n = 1) was administered in 31 patients (55%). A stent-related complication was noted in one patient (stent misplacement). All patients were discharged alive without infarct or need for surgery. There were no events of subacute stent thrombosis; all patients received combined therapy with aspirin and clopidogrel, the latter for 1 month. In one patient who had received abciximab, severe thrombocytopenia (0 platelet count) was detected at 3 days after discharge but it was fully reversible with no sequelae. Over 5.2 +/- 2.8 (range, 1--11) months, there was one sudden death and two clinical restenoses; no other late complication occurred. CONCLUSION: Initial experience with 73 R stents in 56 patients and a consistent approach by a single operator of stent oversizing and high-pressure deployment resulted in high procedural success (100%), lack of stent thrombosis (0%), and a low stent-related complication rate (1.8%), while the design and profile of the R stent allowed for direct stenting in 37.5% of patients. One should be vigilant for the sporadic occurrence of severe thrombocytopenia with use of IIb/IIIa inhibitors.

Adult↗

PubMed2000

Effects of early captopril therapy after myocardial infarction on the incidence of late potentials.

BACKGROUND: Late potentials (LP) on signal-averaged electrocardiography (SAECG), recorded 6 to 30 days after an acute myocardial infarction (AMI), identify patients at risk for late arrhythmic events. Angiotensin-converting enzyme (ACE) inhibitors have been shown to reduce ventricular remodeling and cardiovascular mortality after AMI. HYPOTHESIS: The aim of this study was to investigate the effect of early (< 24 h) administration of captopril on the presence of LP on Days 6-30 after AMI. METHODS: The study included 117 patients with a first AMI; 63 patients (53 men and 10 women, aged 59 +/- 12 years), 35 with an anterior and 28 with an inferior AMI (44 thrombolyzed), received early captopril therapy. The control group consisted of 54 age-matched patients (39 men and 15 women, aged 60 +/- 12 years), 19 with an anterior and 35 with an inferior AMI (31 thrombolyzed, p = NS), who did not receive early therapy with an ACE inhibitor. The mean left ventricular ejection fraction was similar in both groups (48 vs. 46%). Time domain analysis of SAECG was performed using a band-pass filter of 40-250 Hz. Late potentials were considered present if any two of three criteria were met: (1) Filtered QRS duration (QRSD) > 114 ms, (2) root-mean-square voltage of the last 40 ms of the QRS complex (RMS) < 20 microV, and (3) duration of low amplitude (< 40 microV) signal of the terminal portion of the QRS (LAS) > 38 ms. RESULTS: In the two groups of patients there were no differences in mean values of SAECG parameters. No patient was receiving any antiarrhythmic drugs. In the captopril group LPs were present in 9 of 63 patients (14%) and in the control group in 17 of 54 patients (31%) (p = 0.046). There was no difference in the number of patients with a patent infarct-related artery in the two groups (76 vs. 59%). CONCLUSION: Captopril treatment early after an AMI reduces the incidence of LPs recorded on Days 6-30 and may thus favorably affect the arrhythmogenic substrate.

Aged↗