Prognostic significance of present atrial fibrillation on a single office electrocardiogram in patients with atrial fibrillation.

BACKGROUND: Evidence for the association of atrial fibrillation (AF) present on the ECG and cardiovascular outcomes in AF patients is limited. OBJECTIVE: To investigate the prognostic significance of AF on a single surface ECG for cardiovascular outcomes in AF patients. METHODS: A total of 3642 AF patients were prospectively enrolled. Main exclusion criteria were rhythms other than sinus rhythm (SR) or AF. The primary end-point was a composite of all-cause death and hospitalizations for congestive heart failure (CHF). Secondary end-points were all-cause death, CHF hospitalizations, cardiovascular death, myocardial infarction, any stroke and stroke subtypes. Associations were assessed with multivariable Cox proportional hazards models. RESULTS: Mean age was 71 years, 28% were female, and mean follow-up was 3.4 years. Patients with SR on the ECG at study enrolment (56%) were younger (69 vs. 74 years, P < 0.0001), had more often paroxysmal AF (73 vs. 18%, P < 0.0001) and fewer comorbidities. The incidence of the primary end-point was 1.8 and 3.1 per 100 person-years in patients with SR and AF, respectively. The multivariable-adjusted hazard ratio was 1.4 (95% confidence intervals 1.1; 1.7; P = 0.001) for patients with AF on the ECG compared to patients with SR. The hazard ratios (95% confidence intervals) were 1.4 (1.1; 1.8; P = 0.006) for all-cause death, 1.5 (1.2; 1.9; P = 0.001) for CHF and 1.6 (1.1; 2.2; P = 0.006) for cardiovascular death. None of the other associations were statistically significant. CONCLUSIONS: The presence of AF in a single office ECG had significant prognostic implications with regard to mortality and CHF hospitalizations in patients with AF. These patients present a high-risk group and might benefit from intensified treatment.

D-dimer levels for Risk Stratification in Patients with Suspected COVID-19 - A Prospective Observational Study.

BACKGROUND: Elevated D-dimer levels have been observed in COVID-19 and are of prognostic value, but have not been compared to an appropriate control group. METHODS: Observational cohort study including emergency patients with suspected or confirmed COVID-19. Logistic regression defined the association of D-dimer levels, COVID-19 positivity, age, and gender with 30-day-mortality. RESULTS: 953 consecutive patients (median age 58, 43% women) presented with suspected COVID-19: 12 (7.4%) patients with confirmed SARS-CoV-2-infection died, compared with 28 (3.5%) patients without SARS-CoV-2-infection. Overall, most (56%) patients had elevated D-dimer levels (≥0.5mg/l). Age (OR 1.07, CI 1.05-1.10), D-dimer levels ≥0.5mg/l (OR 2.44, CI 0.98-7.39), and COVID-19 (OR 2.79, CI 1.28-5.80) were associated with 30-day-mortality. CONCLUSION: D-dimer levels are effective prognosticators in both patient groups.

Combined clopidogrel and proton pump inhibitor therapy is associated with higher cardiovascular event rates after percutaneous coronary intervention: a report from the BASKET trial.

OBJECTIVE: To investigate whether there is an increased risk of cardiac events with a combined therapy of clopidogrel and proton pump inhibitors (PPIs) after percutaneous coronary intervention (PCI). DESIGN: In the BAsel Stent Kosten Effektivitäts Trial (BASKET), all patients undergoing PCI received 6 months of clopidogrel and were analysed for the use of PPI therapy. Endpoints were major adverse cardiac events (MACE), myocardial infarction (MI), death and target vessel revascularization (TVR) after 36 months. RESULTS: Of 801 patients with available discharge medication data, 109 (14%) received PPIs. Patients who received PPIs were older (66.5 ± 10.5 vs. 63.3 ± 11.3 years, P = 0.006), more likely to be woman (80% vs. 69%, P = 0.009) and have a history of diabetes (29.6% vs. 17.3%, P = 0.002) or gastrointestinal ulcer disease (8.3% vs. 3.3%, P = 0.015) and more often received nonsteroidal anti-inflammatory drugs (7.3% vs. 2.2%, P = 0.003) and corticosteroids (11% vs. 3.6%, P = 0.001) but not aspirin (91.7% vs. 97%, P = 0.008) compared with those who did not receive PPIs. Patients who received PPI therapy had higher rates of MACE (30.3% vs. 20.8%, P = 0.027) and MI (14.7% vs. 7.4%, P = 0.01) but similar rates of death (9.2% vs. 7.4%, P = 0.51) and TVR (20.2% vs. 15.3%, P = 0.2) compared with those who did not. By multivariate analysis, diabetes (hazard ratio 1.83, 95% confidence interval 1.07-3.15) and PPI use (hazard ratio 1.88, 95% confidence interval 1.05-3.37) were the only independent risk factors for MI. CONCLUSION: In a real-world PCI population, the combination of PPIs and clopidogrel was associated with a doubling of MI rates after 3 years. Even after correction for confounding factors, concomitant PPI use remained an independent predictor of outcome emphasizing the clinical importance of this drug-drug interaction.

Adjustments of heart failure medication after implantation of a cardiac resynchronization therapy defibrillator.

AIM: "Optimal" medical therapy is mandatory before implantation of a cardiac resynchronization therapy (CRT) device, but "optimal" is not further specified. We determined the number of patients on a specific drug, the percentages of recommended target doses of the drugs the patients were on and their evolution over time. METHODS: Drug therapy (ACE-inhibitors (ACE-I), AT-receptor antagonists (ARBs), betablockers) of 140 patients with a follow-up of at least one year was studied. Response to CRT was defined as reduction in NYHA class ≥1. RESULTS: Age was 66±9 years, follow-up 43±25 months during which 28 patients (20%) had died. At baseline, 81 % of patients were on a betablocker compared to 95% after 3 years (P-value 0.02). Percentages of target doses were 55±34% and increased to 68±41% after 3 years (P-value <0.02). Percentages were increased in responders (58±40% to 72±32%, P-value 0.01 after 3 years), but not in non-responders (57±31% to 56±38%). At baseline, 97% of patients were on ACE-Is/ARBs and 100% after 3 years. Mean percentages of target doses were 78±43% at implant and between 73±40% and 79±49% during follow-up. Percentages were stable both in responders (83% at implant, 78% after 3 years) and in non-responders (80%/87%, both P-value n.s.). CONCLUSION: Even though quantity and quality of drug therapy at baseline was on an acceptable (betablockers) or high (ACE-Is/ARBs) level, physicians must be very observant on therapy during long-term follow-up, especially on target doses of betablockers in non-responders.

Cardiological diagnostic work-up in stroke patients--a comprehensive study of test results and therapeutic implications.

BACKGROUND AND PURPOSE: In some Western countries, many stroke patients undergo routine tests including ECG, echocardiography, carotid ultrasound and Holter monitoring, even though they have been shown to express limited value in unselected patients. Comprehensive data on yield of tests, especially on consequences taken from positive test results, are scanty. METHODS: Consecutive stroke patients with evidence of ischaemic lesions by imaging techniques were included. Aetiology was determined using TOAST-classifications. Rates of positive test results and their impact on drug therapy, especially anticoagulation were evaluated. RESULTS: Two hundred and forty-one consecutive patients, age 69 +/- 13 years were included. Positive test results were documented in 19% with 12-lead ECG, 24% with carotid ultrasound, 24% with echocardiography and never with Holter monitoring. Overall, in 41% positive test results were present. Apart from echocardiography (37%), a change of therapy resulted in 51-56% of patients with a positive test result. CONCLUSIONS: Even though 12-lead ECG, carotid ultrasound and echocardiography only had relatively low incidences of positive findings, their impact on management in case of positive test results was quite high. Nevertheless, future studies to select patients more appropriately are needed. In contrast, Holter monitoring had no impact and should not be used in routine evaluation of stroke patients.

Epidemiology of atrial fibrillation.

Atrial fibrillation is the most common sustained cardiac arrhythmia in the general population. Unfortunately, current treatment strategies aiming at the elimination of atrial fibrillation have limited long term success rates and significant risks. In this context, recent publications have provided many insights on potentially treatable risk factors for the occurrence of atrial fibrillation, such as alcohol, blood pressure, obesity, inflammation and nutritional factors. In this review, we summarise the current evidence on these risk factors and indicate areas in need of further investigation. The current evidence shows that blood pressure, hypertension and obesity seem to play a key role in the pathogenesis of atrial fibrillation. Preliminary evidence also suggests that inflammation is an important mediator of these associations. Knowledge of these interrelationships may eventually help to develop new treatment strategies and decrease the burden of atrial fibrillation in the general population.

Circadian rhythm of cardiac troponin I and its clinical impact on the diagnostic accuracy for acute myocardial infarction.

BACKGROUND: High-sensitivity cardiac troponin T (hs-cTnT) blood concentrations were shown to exhibit a diurnal rhythm, characterized by gradually decreasing concentrations throughout daytime, rising concentrations during nighttime and peak concentrations in the morning. We aimed to investigate whether this also applies to (h)s-cTnI assays and whether it would affect diagnostic accuracy for acute myocardial infarction (AMI). METHODS: Blood concentrations of cTnI were measured at presentation and after 1 h using four different cTnI assays: three commonly used sensitive (s-cTnI Architect, Ultra and Accu) and one experimental high-sensitivity assay (hs-cTnI Accu) in a prospective multicenter diagnostic study of patients presenting to the emergency department with suspected AMI. These concentrations and their diagnostic accuracy for AMI (quantified by the area under the curve (AUC)) were compared between morning (11 p.m. to 2 p.m.) and evening (2 p.m. to 11 p.m.) presenters. RESULTS: Among 2601 patients, AMI was the final diagnosis in 17.6% of patients. Concentrations of (h)s-cTnI as measured using all four assays were comparable in patients presenting in the morning versus patients presenting in the evening. Diagnostic accuracy for AMI of all four (h)s-cTnI assays were high and comparable between patients presenting in the morning versus presenting in the evening (AUC at presentation: 0.90 vs 0.93 for s-cTnI Architect; 0.91 vs 0.94 for s-cTnI Ultra; 0.89 vs 0.94 for s-cTnI Accu; 0.91 vs 0.94 for hs-cTnI Accu). CONCLUSIONS: Cardiac TnI does not seem to express a diurnal rhythm. Diagnostic accuracy for AMI is very high and does not differ with time of presentation. CLINICAL TRIAL REGISTRATION: NCT00470587, http://clinicaltrials.gov/show/NCT00470587.

Holter monitoring for syncope: diagnostic yield in different patient groups and impact on device implantation.

BACKGROUND: Holter monitoring is routinely used in patients referred for the evaluation of syncope, but its diagnostic value in different patient groups is unclear, as is its impact on device implantation (pacemaker or cardioverter-defibrillator). AIM: To determine the diagnostic yield of Holter monitoring in the routine evaluation of syncope, and its impact on subsequent device implantation. DESIGN: Retrospective record review. METHODS: We reviewed all Holter studies in patients referred with syncope between 2000 and 2005. Strict criteria were applied to determine whether a study was diagnostic. The diagnostic value of Holter monitoring (overall and in five subgroups: age, gender, structural heart disease, ejection fraction, medication) and its impact on the implantation of devices, were determined. RESULTS: Of 4877 Holter studies, 826 were performed in patients with syncope (age 72 +/- 15 years): 71 (8.6%) were considered to explain the syncope. Structural heart disease, ejection fraction and age were significant predictors of a diagnostic study (all p < 0.01), whereas gender and cardiac medication were not. A device was implanted in 33 patients (4.4%) whose initial Holter did not explain their syncope, after mean 7 months, whereas 45 patients (5.4%) received a pacemaker based on the Holter results (p = 0.32). DISCUSSION: The overall diagnostic yield of Holter monitoring in the evaluation of syncope was 8.6%, with dramatic differences between subgroups. Our data suggest that the impact of Holter monitoring on device implantation is generally overestimated.

A randomized trial comparing two different approaches of pacemaker selection.

AIMS: DDD-pacemakers are favoured in patients with sick-sinus-syndrome or AV-block. However, AAI-pacemakers for sick-sinus-syndrome or VDD-pacemakers for AV-block may provide similar benefit with lower costs. The aim is to show that a tailored approach (TA) with arrhythmia-specific pacemaker selection was equal to a standard approach (SA) regarding quality of life (QoL) at lower costs. METHODS AND RESULTS: The study was prospective and randomized with QoL as primary endpoint. Secondary endpoints were a combined endpoint of all-cause mortality, worsening heart failure or angina, atrial fibrillation (AF), stroke, these endpoints individually and costs. Of 198 patients (age 77 +/- 10 years, 43% female, ejection fraction 54 +/- 12%, follow-up 38 +/- 15 months), 94 were randomized to SA and 104 to TA. Thirty-two patients (34%) died in the SA group vs. 25 (24%) in the TA (P= ns). QoL showed no differences in all dimensions. The combined secondary endpoint was reached more frequently with SA (51%) compared to TA (37%, P = 0.045). There was no difference regarding all single secondary endpoints. Hardware costs were reduced by 15% (P < 0.0001). CONCLUSION: In long-term follow-up, a TA is equal to SA regarding the primary endpoint QoL and secondary endpoints as AF and mortality. Depending on the healthcare system, it may significantly reduce costs.

Impact of contemporary emergency percutaneous coronary angioplasty for acute myocardial infarction on length of hospital stay.

QUESTIONS UNDER STUDY: Compared to thrombolysis, acute percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI) allows both immediate revascularisation and identification of additional relevant stenosis, so that subsequently no further risk stratification should be necessary and hospital stay shortened. Our aim was to evaluate the impact of PCI on outcome and length of hospital stay after MI compared to that in the thrombolysis era. METHODS: Retrospective evaluation in a Swiss tertiary referral centre of 105 patients with AMI undergoing emergency PCI, who initially were neither in cardiogenic shock nor transferred to another primary or secondary care hospital for further treatment. Main outcome measurement was length of overall hospital stay. Additional measurements included mortality, left ventricular function, and time point of the last major adverse cardiac event (MACE). RESULTS: Overall hospitalisation time was 11.1 +/- 6.8 days, thus being only 1.5 days shorter than in the thrombolysis era. Age above 70 or type of infarction did not influence hospitalisation time, but age below 60 years did. In-hospital mortality was 1%. Left-ventricular function was considerably impaired (<35%) in 6 patients. After the sixth hospital day, 97% of MACE had occurred. According to a validated risk score, 92% of patients belonged to a low risk group with a 30-day mortality risk of 1.4% or less and could have been discharged not later than day 6. CONCLUSIONS: Our data suggest that an early discharge strategy, although safe in low risk patients is not followed at the present time. This approach could further reduce costs without jeopardizing outcome.

Selection bias of elderly patients with chronic angina referred for catheterization.

BACKGROUND: Registry patients are generally older and more sick than patients enrolled in trials questioning the generalizability of trial results. We assessed whether such a selection bias also exists in elderly patients with chronic angina referred for catheterization. METHODS AND RESULTS: All 119 patients age>or=75 years with Trial of Invasive versus Medical Therapy in the Elderly (TIME) inclusion but no major exclusion criteria referred for catheterization during the TIME trial inclusion period in four TIME centers were registered and followed-up for one year. Registry patients differed from the 188 trial patients in the same hospitals in that they were younger, somewhat more frequently male, with less antianginal drugs and studied more often after acute chest pain at rest but with more comorbidities than study patients. Left ventricular ejection fraction and vessel disease were similar. One year mortality was 11.4% in registry and 9.6% in invasive TIME patients but differences disappeared after adjustment for baseline differences. Symptomatic status after one year was similar too. CONCLUSIONS: In elderly patients with chronic angina, a bias in the selection for invasive management exists which seems different from that reported in younger patient settings. After adjustment for these selection factors, however, one-year outcome was remarkably similar in registry and trial patients.

Intermittent pacemaker dysfunction caused by digital mobile telephones.

OBJECTIVES: This study was designed to evaluate possible interactions between digital mobile telephones and implanted pacemakers. BACKGROUND: Electromagnetic fields may interfere with normal pacemaker function. Development of bipolar sensing leads and modern noise filtering techniques have lessened this problem. However, it remains unclear whether these features also protect from high frequency noise arising from digital cellular phones. METHODS: In 39 patients with an implanted pacemaker (14 dual-chamber [DDD], 8 atrial-synchronized ventricular-inhibited [VDD(R)] and 17 ventricular-inhibited [VVI(R)] pacemakers), four mobile phones with different levels of power output (2 and 8 W) were tested in the standby, dialing and operating mode. During continuous electrocardiographic monitoring, 672 tests were performed in each mode with the phones positioned over the pulse generator, the atrial and the ventricular electrode tip. The tests were carried out at different sensitivity settings and, where possible, in the unipolar and bipolar pacing modes as well. RESULTS: In 7 (18%) of 39 patients, a reproducible interference was induced during 26 (3.9%) of 672 tests with the operating phones in close proximity (<10 cm) to the pacemaker. In 22 dual-chamber (14 DDD, 8 VDD) pacemakers, atrial triggering occurred in 7 (2.8%) of 248 and ventricular inhibition in 5 (2.8%) of 176 tests. In 17 VVI(R) systems, pacemaker inhibition was induced in 14 (5.6%) of 248 tests. Interference was more likely to occur at higher power output of the phone and at maximal sensitivity of the pacemakers (maximal vs. nominal sensitivity, 6% vs. 1.8% positive test results, p = 0.009). When the bipolar and unipolar pacing modes were compared in the same patients, ventricular inhibition was induced only in the unipolar mode (12.5% positive test results, p = 0.0003). CONCLUSION: Digital mobile phones in close proximity to implanted pacemakers may cause intermittent pacemaker dysfunction with inappropriate ventricular tracking and potentially dangerous pacemaker inhibition.

Time dependence of left ventricular recovery after delayed recanalization of an occluded infarct-related coronary artery: findings of a pilot study.

OBJECTIVES: We sought to test the hypothesis that late recanalization of infarct-related coronary arteries (IRAs) improves long-term left ventricular (LV) function. BACKGROUND: Reperfusion within 24 h of an acute myocardial infarction (MI) has been shown to improve myocardial healing and to reduce infarct expansion. Uncontrolled data suggest that there may be a time window of several weeks for such an effect. METHODS: Sixteen asymptomatic patients 10 +/- 4 days after a first Q wave anterior wall MI with persistent left anterior descending coronary artery occlusion and infarct-zone akinesia were randomized to immediate (2 weeks) or delayed (3 months) angioplasty. Repeat catheterization and cardiac magnetic resonance imaging (MRI) were performed after 3 and 12 months. RESULTS: Angiography 3 months after MI revealed that LV ejection fraction (LVEF) had increased ([mean +/- SD] 54.4 +/- 4.3% vs. 63.9 +/- 7.4%, p < 0.01) as a result of improved regional function (p < 0.01) and LV end-systolic volume had decreased (p < 0.002), whereas LV end-diastolic volume remained unchanged. With delayed angioplasty, LVEF, infarct zone wall motion and LV volumes did not improve. Cardiac MRI at baseline and at 3 and 12 months confirmed these findings and extended them up to 1 year, indicating that delayed angioplasty could no longer improve LV function because of marked LV dilation (p < 0.01). Immediate angioplasty had a high success rate, but restenosis (50%) was accompanied by new severe angina as a clinical indicator of salvaged myocardium, which did not occur after delayed angioplasty. CONCLUSIONS: This pilot study in selected patients supports the hypothesis that myocardial viability persists ("hibernation") for 2 to 3 weeks but not for 3 months after MI, during which time it may be worthwhile to restore blood flow to a large myocardial territory, even in asymptomatic patients, to improve long-term LV function.

Use of copeptin and high-sensitive cardiac troponin T for diagnosis and prognosis in patients with diabetes mellitus and suspected acute myocardial infarction.

BACKGROUND: Diabetes is a major risk factor for acute myocardial infarction (AMI). Assessment of diabetic patients is challenging due to an often atypical presentation of symptoms. We aimed to evaluate the two novel biomarkers copeptin and high-sensitive cardiac troponin (hs-TnT) for the improvement of early diagnosis and risk-stratification in patients with diabetes and suspected AMI. METHODS: In this prospective international multicenter study we evaluated 379 patients with diabetes in a cohort of 1991 patients presenting with symptoms suggestive of AMI. The measurement of biomarkers was performed at presentation. RESULTS: Among the 379 diabetic patients, 32.7% had AMI, and in the 1621 patients without diabetes, 18.8% had AMI. The additional use of copeptin improved the diagnostic accuracy provided by conventional troponin alone (AUC 0.86 vs. 0.79, p=0.004). During a median follow-up of 814 days, 49 (13.1%) diabetic patients died. Cumulative 2-year survival rate for patients with copeptin levels below 9 pmol/l was 96.6% compared to 82.8% in patients above that level (p<0.001). The same was observed for hs-TnT with a cutoff level of 14 ng/l (97.7% vs. 82.0%, p<0.001) respective of cTnT with a cutoff level of 10 ng/l (93.5% vs. 75.6%, p<0.001). In multivariate Cox analysis, copeptin, hs-TnT and cTnT were strong and independent predictors of 24-month-mortality. Using the dual marker strategy (copeptin and troponin) identified two groups of high-risk patients where 22.5% of the group with hs-cTnT and copeptin above the cutoff and 28.6% with cTnT and copeptin above the cutoff died. CONCLUSION: In diabetic patients, copeptin only slightly improves the early diagnosis of AMI provided by hs-cTnT. However, both markers (copeptin and troponin) predict long-term mortality accurately and independently of each other.

Value of routine holter monitoring for the detection of paroxysmal atrial fibrillation in patients with cerebral ischemic events.

BACKGROUND AND PURPOSE: Holter monitoring for the detection of paroxysmal atrial fibrillation (PAF) is a routine procedure after cerebral ischemic events, although its value is unknown. The aim of this study was to evaluate the incidence of PAF and its impact on drug treatment modifications in this population. METHODS: Retrospective evaluation of all Holter ECGs in patients with cerebral ischemic events was done. Chart analysis with regard to drug treatment modification and cardiovascular drug therapy was performed in all patients. RESULTS: Between January 2000 and December 2002, 425 hospitalized patients (median age, 68 years) had routine Holter ECG after a cerebral ischemic event. PAF was diagnosed in 9 patients (2.1%): in 2, oral anticoagulation was contraindicated; 1 had severe carotid stenosis as an additional risk factor; 1 had PAF but was on oral anticoagulation for basilar thrombosis; 2 had had PAF before and were on aspirin; and 3 had a new diagnosis of PAF. The last 5 patients were put on oral anticoagulation. Thus, routine Holter ECG resulted in drug treatment modification in only 5 of 425 patients (1.2%). CONCLUSIONS: PAF in cerebral ischemic event patients has a low incidence and, if diagnosed, rarely leads to drug modification. Therefore, routine Holter monitoring for PAF screening is not recommended in this patient population.

Mechanism of sustained monomorphic ventricular tachycardia in systemic sclerosis.

Three patients with advanced systemic sclerosis and recurrent or incessant monomorphic ventricular tachycardia underwent cardiac electrophysiologic studies. Biventricular transcatheter mapping showed findings most compatible with a reentrant mechanism, which was effectively treated with transcatheter ablation.

The treatment of patients with infected implantable cardioverter-defibrillator systems.

OBJECTIVE: The purpose of this study was to evaluate the treatment of patients with infected implantable cardioverter-defibrillator systems. METHODS: Retrospective analysis was done of the cases of 21 patients treated for implantable cardioverter-defibrillator infection during an 11-year period. RESULTS: Of 723 cardioverter-defibrillator implantations (550 primary implants, 173 replacements), nine (1.2%) were complicated by early postoperative device-related infections. Late infections developed in two patients 19 and 22 months, respectively, after implantation. Ten other patients were transferred to our institution for treatment of cardioverter-defibrillator infection. The time from implantation to overt infection was 2.2 +/- 1.3 months, excluding the two late infections. The responsible organisms were Staphylococcus aureus (9), Staphylococcus epidermidis (6), Streptococcus hemolyticus (1), gram-negative bacteria (3), Candida albicans (1), and Corynebacterium (1). All patients were treated with intravenous antibiotic drugs. Total system removal was done in 15 patients and partial removal in 2; in 4, the cardioverter-defibrillator system was not explanted. There were no perioperative deaths. A new implantable cardioverter-defibrillator system was reimplanted in 7 patients after 2 to 6 weeks of antibiotic therapy. Ten patients were treated without reimplantation (2 arrhythmia operation, 8 antiarrhythmic drugs). Four patients (3 patients without explantation and 1 with partial system removal) were treated with maintenance long-term antibiotic therapy. During a mean follow-up of 21 +/- 2.8 months, no patient had clinical recurrence of infection. One patient treated with antiarrhythmic drugs without system reimplantation died suddenly. CONCLUSIONS: Infections that involve implantable cardioverter-defibrillator systems can be safely managed by removing the entire system with reimplantation after intravenous antibiotic therapy. In selected patients in whom the risk for system explantation is high and anticipated life expectancy is short, long-term antibiotic therapy to suppress low-virulence infections may represent an acceptable alternative.

Placement of a temporary pacemaker electrode through a persistent left superior vena cava.

Perioperative temporary pacing was needed in a patient with congenital skeletal malformations and a cardiac conduction disturbance with incomplete trifascicular block. We report the successful placement of the pacemaker electrode through a persistent left superior vena cava (SVC).

Prevention of supraventricular tachyarrhythmias after open heart operation by low-dose sotalol: a prospective, double-blind, randomized, placebo-controlled study.

BACKGROUND: The aim of this prospective, double-blind, placebo-controlled trial was to assess the preventive effect and safety of low-dose sotalol after heart operation. METHODS: Two hundred fifty-five consecutive patients referred for elective coronary artery bypass grafting (n = 220) or aortic valve operation (n = 35) were randomized to receive either 80 mg of sotalol twice daily (n = 126) or matching placebo (n = 129) for 3 months, with the first dose given 2 hours before operation. RESULTS: There were no significant baseline differences between the groups. Overall, supraventricular tachyarrhythmias occurred in 36% of patients (82% atrial fibrillation). Hospital stay was 11.6 +/- 5 days in patients with supraventricular arrhythmias, versus 9.5 +/- 2.4 days in patients without it (p < 0.0001). Low-dose sotalol reduced the rate of supraventricular arrhythmias from 46% (placebo) to 26% (sotalol; p = 0.0012), or by 43%. On the fourth postoperative day, heart rate was lower in the sotalol group (74 +/- 12 beats/min versus 85 +/- 15 beats/min; p < 0.0001) but the QT interval corrected for the heart rate was not prolonged (sotalol group, 0.44 +/- 0.03 second; placebo group, 0.43 +/- 0.03 second; p = not significant). Study medication had to be discontinued because of side effects in 5.6% of sotalol and 3.9% of placebo patients (p = not significant), with one possible proarrhythmic event occurring in a patient receiving sotalol. CONCLUSIONS: Because more than 90% of supraventricular arrhythmic episodes occurred within 9 days after operation and 70% of all possibly sotalol related side effects occurred after day 9, the findings in this study imply that prophylactic treatment with sotalol may be limited to the first 9 postoperative days.

Predictors of loss of atrioventricular synchrony in single lead VDD pacing.

OBJECTIVE: To evaluate maintenance of proper VDD function, defined as persistence of sinus rhythm with atrial synchronous ventricular pacing, and to define factors predicting failure of the VDD mode in patients with atrioventricular (AV) block and normal sinus function. DESIGN: Observational study in 86 consecutive patients (mean (SD) age 74 (12) years; 38 women, 48 men) with single lead VDD pacing systems (Intermedics Unity, n = 66, Medtronic Thera VDD, n = 20), implanted for high degree AV block with documented normal sinus node. Pacemaker function was assessed by event counters, telemetric measurements, and Holter recordings. Demographic, radiological, and pacing variables were correlated with loss of proper VDD function. RESULTS: During a mean (SD) follow up of 10 (10) months (range 1-37), sinus rhythm and atrial triggered ventricular pacing were maintained in 70 of 86 patients (81%). Atrial undersensing was observed in nine patients, lead migration in two, atrial fibrillation in three, and symptomatic sinus bradycardia in two. Univariate predictors of loss of proper VDD function were: low position of the atrial dipole relative to the carina (> or = 6 cm; p < 0.01) during fluoroscopy; and maximum programmable atrial sensitivity of the pacemaker (p = 0.03). In a multivariate analysis, only dipole position remained predictive of outcome (p < 0.02). Not predictive were sex, age, symptoms before pacemaker implantation, cardiothoracic ratio or dilatation of individual heart chambers on chest x ray, side of device implant, and P wave amplitude at implant. CONCLUSIONS: To maintain proper VDD function in the long term, a low anatomical dipole position relative to the carina should be avoided. Electrical guidance of dipole positioning does not seem to influence long term outcome.