Malignant melanoma has an aggressive biological behaviour and a high rate of cardiac involvement. As shown from post-mortem studies, metastases of melanoma can involve any organ and cardiac metastases are frequent. This report describes a case of widespread malignant melanoma in a patient with clinical presentation of complete atrioventricular (AV) block. Thorax CT and transthoracic echocardiography revealed a mass involving the conduction system. By VDD permanent pacing (atrial synchronous ventricular pacing), haemodynamic stability was maintained and the patient remains under follow-up receiving chemo-immunotherapy. In the retrospective analysis of the patient's records, we realized that the AV conduction delay had been progressing for at least 7 months. Cardiac metastasis of malignant melanoma is a common finding and can proceed in the absence of overt clinical manifestations. Therefore, the clinician should be alert to the development of cardiac signs and symptoms in a metastatic melanoma patient and should perform a detailed cardiac examination to exclude cardiac metastasis of the tumour.
A long QT interval, which is the surface electrocardiogram (ECG) manifestation of a prolonged repolarization phase, is associated with an increased risk of torsade de pointes (TdP). If transient, it may present with syncope, and if is not transient, it may cause sudden death. A long QT interval may be congenital or acquired. The most common cause of an acquired long QT interval is drug administration (1). The drugs that interfere with potassium influx, commonly by blocking the human ether-a-go-go-related gene channel-dependent potassium current (as with fluoroquinolones) in myocyte membranes produce a prolongation of the corrected QT (QTc) interval and increase the risk of spontaneous arrhythmia generation (2). Fluoroquinolones have been reported to prolong the QTc interval and precipitate TdP in patients at high risk (1,3). We present a patient with bradycardia who developed TdP during oral moxifloxacin therapy for pneumonia. CASE PRESENTATIONAn 87-year-old woman with hypertension, chronic renal failure and dementia was admitted to the emergency department with presyncope. Junctional rhythm with a rate of 30/min was present on ECG, and the QT interval was 0.66 s; the QTc interval, according to Bazett's formula, was 0.47 s (Figure 1). There were no previous ECGs performed. Medications she was using at the time of admission included ginkgo glycosides (19.2 mg/day), valsartan 80 mg plus hydrochlorothiazide (12.5 mg/day), acetylsalicylic acid (100 mg/day) and citalopram (20 mg/day). Her serum creatinine level was 283 μmol/L and potassium level was 4.2 mmol/L at admission. Other biochemical tests were normal. A temporary transvenous cardiac pacemaker was implanted and set to a rate of 60 beats/min. The pacemaker was turned off 24 h after the implantation because sinus rhythm resumed, but it was left in place in case of bradycardia. On that day, 400 mg/day oral moxifloxacin was prescribed to the patient for aspiration pneumonia. At the beginning of moxifloxacin treatment, the rhythm was normal, with normal QT (0.40 s) and QTc (0.43 s) intervals at a heart rate of 68 beats/min. The patient was transferred to the intensive care unit for telemetric follow-up due to the possible recurrence of symptomatic bradycardia. Intermittant junctional rhythms were observed on the monitor, but sinus rhythm was dominant. On the fourth day of moxifloxacin therapy, TdP developed following a short-long-short sequence of junctional rhythm (Figure 2) and recovered spontaneously after 36 s. The QT interval on the ECG taken on the same Torsade de pointes occuring due to a long QT interval is a rare but potentially fatal arrhythmia. Acquired long QT develops most commonly because of drugs that prolong ventricular repolarization. It has been reported that fluoroquinolone antimicrobials prolong the corrected QT interval but rarely cause torsade de pointes. A patient with torsade de pointes risk factors (female sex, advanced age, extreme bradycardia and renal failure) who developed the condition on the fourth day of 400 mg/day of oral moxifloxa...
SUMMARYDuring implantable cardioverter-defibrillator (ICD) implantation, ventricular defibrillation testing (DFT) is considered a standard procedure. This procedure often requires multiple ventricular fibrillation (VF) inductions. These repeated short episodes of circulatory arrest with global cerebral ischemia may cause neurological damage. In the present study, patients undergoing initial ICD implantation and limited induction of VF for defibrillation safety margin testing were evaluated for pre-and postoperative cognitive and neurologic functions. In addition, the serum neuron specific enolase (NSE) level, which is a biochemical marker of cerebral injury, was evaluated.The study was performed on 16 patients undergoing initial elective transvenous insertion of an ICD. A neurologic examination and cognitive assessment tests were performed 24 to 48 hours before and after ICD. NSE was determined before (NSE 1) and at the end of the surgery (NSE 2), as well as 2 hours (NSE 3), 24 hours (NSE 4), and 48 hours (NSE 5) after implantation.A total of 29 internal shocks (average, 1.8 ± 0.4) with energy ranging from 14 to 41 J (mean, 20 ± 5; median, 20 J ) were delivered in the ICD group patients. In one patient, 3 external (50, 200 and 360 J) shocks were required for fast VT induced during ICD lead positioning. The mean duration of VF was 10 ± 4 seconds and the mean cumulative time in VF was 16 ± 5 seconds. The mean recovery time between VFs was 5.3 ± 0.6 minutes. NSE levels were not different from the baseline at any time point in the patients of the group that completed the 48-hour observation period (P > 0.05). The patients did not report any new neurological symptoms after ICD implantation, and repeat examination after the procedure showed no abnormal findings other than those detected in the previous one. There were no statistically significant differences between the preoperative and postoperative scores obtained in the cognitive assessment.Single or two VF inductions and the brief arrest of cerebral circulation during ICD implantation are not associated with permanent neurological injury. However, further studies are needed to confirm this finding. (Int Heart J 2008; 49: 553-563)
SummaryBackground: The relation between heart rate variability (HRV) and occurrence of atrial fibrillation (AF) in paroxysmal AF has been well studied, but there are controversial observations regarding the relation of HRV parameters to the recurrence of chronic AF after cardioversion.Hypothesis: The present study compared HRV parameters of patients with chronic AF on the second day of cardioversion with a healthy control group and investigated their predictive value for AF recurrence.Methods: Forty-one patients with chronic AF (> 3 months), who had various underlying cardiovascular disorders, were enrolled to the study. Of these, 31 patients were successfully cardioverted by external direct current shock, but 27 patients fulfilled the entry criteria. Twenty healthy subjects served as a control group. On the second day of restoration of sinus rhythm, 24-h Holter recording was obtained and the following time-domain indices of HRV were measured: SDNN (the standard deviation of the mean RR interval expressed in ms), SDANN (the SD of the averages of RR intervals in all 5-min segments of the 24-h recording), rMSSD (the root mean square of differences of successive RR intervals), and pNN50 (the percentage of adjacent RR intervals that differed by more than 50 ms). Patients were followed-up for 6 weeks for recurrence of AF.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.