Implantable cardioverter-defibrillator shock: appropriate or inappropriate?

A 76-year-old female with a single chamber implantable cardioverter-defibrillator implanted for secondary prevention was referred due to multiple discharges. The device was programmed for ventricular tachycardia (VT) detection at 400 ms, fast VT detection at 280 ms, and ventricular fibrillation detection at 320 ms. Antitachycardia pacing (ATP) during charge was enabled. Interrogation revealed a VT episode with a mean cycle length of 270 ms, which was successfully terminated with ATP during charge. Seconds later, the device delivered a shock. This case illustrates the importance of understanding programming algorithms as part of troubleshooting when facing a scenario of device discharge.

Physiotherapy and cardiac rhythm devices: a review of the current scope of practice.

AIMS: Several case reports have demonstrated negative interactions between various physiotherapy modalities and cardiac rhythm devices (CRD). Fear of these potential interactions may lead to suboptimal utilization of physiotherapy treatments in CRD patients. No prior review of available guidelines, or management strategies, on the interaction between physiotherapy modalities and CRD patients has been reported. To review existing guidelines regarding the use of physiotherapy modalities in patients with pacemakers and/or implantable cardioverter-defibrillators (ICDs). To retrospectively analyse CRD patient encounters at a local physiotherapy facility during a period of 2 years. METHODS AND RESULTS: A review of the literature regarding the potential interactions between physiotherapy modalities and CRDs was performed. Next, a 2 year retrospective analysis of patient encounters at a physiotherapy facility was conducted. In addition, seven international physiotherapy societies and four CRD manufacturers were surveyed with respect to recommendations regarding physiotherapy treatments in device patients. The local physiotherapy facility treated 25 patients with CRD (22 pacemaker and 3 ICD patients) for a total of 230 visits (9.2 visits/patient). Five patients received transcutaneous electrical nerve stimulation (TENS) and all 25 were administered additional treatment in the form of ultrasound (15), acupuncture (19), Laser (7), traction/manual therapy (12), exercise (8), education (18), taping (5), and/or moist heat (5). No complications occurred. Meanwhile, international societies and device manufacturers offered few specific or consistent recommendations. CONCLUSION: There are no specific international policies regarding the administration of physiotherapy modalities in CRD patients and, thus, there are no specific guidelines to be implemented at the local level. Review of the literature and of recommendations from CRD manufacturers suggests that TENS, Diathermy, and Interferential Electrical Current Therapy are best avoided in patients with CRDs. However, there is no consensus and it may be possible to safely deliver these modalities in a proper setting with device and patient monitoring. Although further research is required in this regard, active collaboration between physiotherapists and CRD clinic physicians should allow for the safe application of most physiotherapy modalities.

Atrial fibrillation in the pacemaker clinic.

BACKGROUND: Electrocardiographic (ECG) recognition of the underlying rhythm in patients with ventricular pacing can be difficult. Atrial fibrillation (AF) in particular may go unreported. OBJECTIVES: To compare the underlying atrial rhythm determined in the pacemaker clinic with the 12-lead ECG interpretation of the atrial rhythm in those who were continuously paced in the ventricle. It was intended to determine whether long term anticoagulation therapy was related to whether AF was diagnosed before or after pacemaker implantation. METHODS: Pacemaker clinic patients were enrolled if they had a 100% paced ventricular rhythm. The underlying rhythm was determined using pacemaker programming manoeuvres. A 12-lead ECG was recorded on all patients within 10 min of their pacemaker assessment and interpreted by one of the several geographic full-time cardiologists at the centre. All cardiologists were blinded to the results of pacemaker assessment and to the clinical history. RESULTS: Fifty-six patients were enrolled. At the pacemaker clinic, 37 were determined to be in AF and three were in atrial flutter (AFL). Of these 40 patients with AF/AFL, 28 were correctly identified as such on the 12-lead ECG interpretation. Twelve of the 40 were interpreted only as having an 'electronic ventricular pacemaker' (EVP). Sixteen of the 40 patients (40.0%) with AF or AFL were not taking warfarin. Twenty-two of 25 patients with an AF/AFL diagnosis before pacemaker implantation were taking warfarin, compared with two of 15 patients with AF/AFL diagnosis after pacemaker implantation (P<0.0001). CONCLUSION: These results show that the underlying rhythm in patients with ventricular pacing is frequently unrecognized by routine ECG interpretation. This may be of particular importance in the AF/AFL population as a potential contributor to the underuse of warfarin, especially when AF develops after pacemaker implantation. The pacemaker clinic may be in a position to play an important role in the identification of these patients.