Are there increased periprocedural complications with the MRI-conditional Medtronic Revo SureScan Pacing System? : A meta-analysis.

BACKGROUND: The use of magnetic resonance imaging (MRI)-conditional permanent pacemakers has increased significantly. In this meta-analysis, we examine the safety of MRI-conditional pacing systems in comparison with conventional systems. METHODS: An electronic search was performed using major databases, including studies that compared the outcomes of interest between patients receiving MRI-conditional pacemakers (MRI group) versus conventional pacemakers (control group). RESULTS: Six studies (5 retrospective and 1 prospective non-randomised) involving 2,118 adult patients were identified. The MRI-conditional pacemakers, deployed in 969 patients, were all from a single manufacturer (Medtronic Pacing System with 5086 leads). The rate of pacemaker lead dislodgement (atrial and ventricular) was significantly higher in the MRI group (3% vs. 1%, OR 2.47 (95% CI 1.26; 4.83), p = 0.008). The MRI group had a significantly higher rate of pericardial complications (2% vs. 1%, OR 4.23 (95% CI 1.18; 15.10), p = 0.03) and a numerically higher overall complication rate in comparison with the conventional group (6% vs. 3%, OR 2.02 (95% CI 0.88; 4.66), p = 0.10) but this was not statistically significant. CONCLUSIONS: In this meta-analysis, the rates of pacemaker lead dislodgement and pericardial complications were significantly higher with the Medtronic MRI-conditional pacing system.

Effects of magnesium on atrial fibrillation after cardiac surgery: a meta-analysis.

OBJECTIVES: To assess the efficacy of the administration of magnesium as a method for the prevention of postoperative atrial fibrillation (AF) and to evaluate its influence on hospital length of stay (LOS) and mortality. METHODS: Literature search and meta-analysis of the randomised control studies published since 1966. RESULTS: 20 randomised trials were identified, enrolling a total of 2490 patients. Study sample size varied between 20 and 400 patients. Magnesium administration decreased the proportion of patients developing postoperative AF from 28% in the control group to 18% in the treatment group (odds ratio 0.54, 95% confidence interval (CI) 0.38 to 0.75). Data on LOS were available from seven trials (1227 patients). Magnesium did not significantly affect LOS (weighted mean difference -0.07 days of stay, 95% CI -0.66 to 0.53). The overall mortality was low (0.7%) and was not affected by magnesium administration (odds ratio 1.22, 95% CI 0.39 to 3.77). CONCLUSION: Magnesium administration is an effective prophylactic measure for the prevention of postoperative AF. It does not significantly alter LOS or in-hospital mortality.

Electroanatomic mapping of arrhythmogenic right ventricular dysplasia.

OBJECTIVES: We tested the hypothesis that spatial association of low-amplitude intracardiac electrograms can identify the presence, location and extent of dysplastic regions in arrhythmogenic right ventricular dysplasia (ARVD). BACKGROUND: Arrhythmogenic right ventricular dysplasia is a right ventricular (RV) cardiomyopathy characterized pathologically by fibrofatty infiltration and clinically by a spectrum of arrhythmias, sudden cardiac death and RV failure. Diagnosis of ARVD still remains a clinical challenge. METHODS: A three-dimensional electroanatomic mapping technique was used to map the RV of two groups of patients: 1) those with ARVD presenting with typical clinical, electrocardiographic and echocardiographic or magnetic resonance imaging (MRI) findings; and 2) those with structurally normal ventricles. RESULTS: The dysfunctional RV area could be identified only in the first group and was characterized by the presence of discrete areas of abnormally low-amplitude electrograms. Hence, the normal voltage values observed in the control group (unipolar: 11.9 +/- 0.3 mV; bipolar: 4.6 +/- 0.2 mV [mean +/- SEM]) and in the nonaffected zones in the ARVD group (unipolar: 10.4 +/- 0.2 mV; bipolar: 4.6 +/- 0.2 mV) were reduced significantly (p < 0.05) in the dysplastic areas (unipolar: 3.3 +/- 0.1 mV; bipolar: 0.5 +/- 0.1 mV). The pathologic process mainly involved the RV anterolateral free wall, apex and inflow and outflow tracts and ranged from patchy areas to uniform and extensive involvement. Concordance between electroanatomic findings and MRI or echocardiographic findings was noted in all patients. CONCLUSIONS: The pathologic substrate in ARVD can be identified by spatial association of low-amplitude endocardial electrograms, reflecting replaced myocardial tissue. The ability to accurately identify the presence, location and extent of the pathologic substrate may have important diagnostic, prognostic and therapeutic implications.

Reversible pancreatitis, hepatitis, and peripheral polyneuropathy associated with parenteral gold therapy.

A 63-year-old man with seronegative rheumatoid arthritis developed acute pancreatitis, severe hepatitis, and sensorimotor polyneuropathy after receiving 150 mg of intramuscular aurothioglucose (gold). Positive lymphocyte transformation test to gold indicated a cell mediated hypersensitivity to the drug, while multiple investigations ruled out other underlying causes for his illness. After cessation of gold therapy a complete recovery occurred.

The acute effect of minocycline on the pericardium: experimental and clinical findings.

STUDY OBJECTIVES: To evaluate the acute effect of minocycline on the pericardium in the experimental animal and in the human with malignant pericardial disease. DESIGN: A prospective study in open-chest dogs and in humans. SETTING: Experimental surgery laboratory, medical school; coronary care unit, university hospital. METHODS: Twenty-three open-chest dogs were divided into four groups according to the solution injected intrapericardially: (1) minocycline, 5 mg/kg; (2) minocycline, 10 mg/kg; (3) normal saline solution, 100 mL, followed by minocycline, 10 mg/kg; (4) a mixture of 50 mL of the dog's own blood mixed ex vivo with minocycline, 10 mg/kg to evaluate the effect of rising pH of minocycline solution. The extent of myocardial injury is evaluated by measuring ST-T segment deviation in six standard bipolar leads and in three unipolar electrograms recorded over the left ventricular pericardial surface. The pH of the various minocycline solutions is measured. Nine consecutive patients with malignant cardiac tamponade receiving minocycline intrapericardially are evaluated for the appearance of chest pain and ECG changes. RESULTS: Minocycline (5 and 10 mg/kg) caused marked, transient ST-T segment deviation in all dogs, whether or not saline solution was previously injected into the pericardial sac. Prior mixing of minocycline with blood markedly increased the acidic pH of the minocycline solution and significantly reduced the extent of ST-T segment deviation. Four of nine patients had chest pain during minocycline injection. None had ST-T segment changes. CONCLUSION: Minocycline causes a marked, transient injury to the epicardial-pericardial surface. Our animal and in vitro studies indicate that this acute injury is probably partly related to the acidic pH of the minocycline solution. Our experimental findings suggest that this minocycline-induced injury may be reduced by raising the pH of the solution either ex vivo (eg, by mixing minocycline with previously withdrawn pericardial fluid) or in vivo (eg, by leaving 200 to 300 mL of pericardial fluid prior to minocycline injection). Limited experience in the human with malignant cardiac tamponade indicates that intrapericardial minocycline is usually well tolerated, although severe chest pain may appear.

Intrapericardial minocycline sclerosis for malignant pericardial effusion.

STUDY OBJECTIVE: To evaluate the effectiveness and safety of minocycline hydrochloride (minocycline) intrapericardially in patients with malignant pericardial effusion. DESIGN: Consecutive patients admitted to the hospital during a 32-month period received intrapericardial minocycline. SETTING: A 900-bed university hospital. PATIENTS: Fourteen consecutive patients with malignant pericardial effusion. INTERVENTION: Following percutaneous insertion of a pericardial drain, minocycline was administered at a dosage of 10 mg/kg every 48 h until fluid drainage stopped or until further therapy was deemed necessary. MEASUREMENTS: Complications associated with therapy, total minocycline requirements, immediate and late failure of therapy, and clinical and echocardiographic follow-up of at least 6 months. RESULTS: Mean amount of minocycline administered was 1.9 +/- 1.0g given in 2.4 divided doses. Total drainage time was 5.4 +/- 2.5 days. Recurrence of malignant pericardial effusion was seen in only 1 of 14 patients. Death occurred in 10 patients due to severe metastatic disease in all. Minocycline instillation was associated with severe chest pain in seven patients, and with ECG changes suggesting pericardial or subepicardial injury in two patients. CONCLUSION: (1) Intrapericardial minocycline instillation is very effective in preventing recurrence of malignant pericardial effusion. (2) Minocycline is irritative to the pericardium and may cause severe chest pain with transient ECG changes, suggesting pericardial or subepicardial injury.