Refusal of implantable cardioverter defibrillator generator replacement: the nurse's role.

An adult patient who is conscious and mentally competent has the right to refuse any medical or surgical procedure even when the best medical opinion deems it necessary for life. The doctrine of informed consent is grounded on the premise that a physician's judgment is subservient to the patient's right to self-determination. Some suggestions for the future are offered. It may be beneficial to have a formal doctrine of informed refusal incorporated into the existing system of informed consent thus having patients sign a refusal of treatment form just as they sign a form consenting to treatment. Even if the physician and patient share an ideal relationship that includes mutual respect and participation in decision making, the consent to treatment or refusal of treatment should be documented both on a form and in the physician's own words in the patient record to avoid any discrepancies that may arise later. Items that may eventually be added to the list of requirements for informed consent or refusal include the impact of the treatment or procedure on the patient's job or family situation, impact on quality of life, and the potential long-term cost to the patient or to public or private health care payers.

Combined ambulatory electroencephalographic and electrocardiographic recordings for evaluation of syncope.

Evaluation of patients with syncope often includes a battery of noninvasive tests. In this study, 45 patients (26 with suspected neurologic and 19 with suspected cardiac syncope) were evaluated with simultaneous 24-hour electroencephalographic (EEG) and 2-channel electrocardiographic (ECG) recordings. Isolated cardiac rhythm abnormalities were noted in 21 patients, but none of these was symptomatic and no definitive arrhythmias occurred. Isolated EEG abnormalities were noted in 11 patients, 5 of whom had EEG abnormalities consistent with seizure disorders. Simultaneous EEG and ECG abnormalities were seen in 4 patients. In 2 cases, a previously unsuspected etiology for syncope was found: seizures in 1 patient with heart disease, and sinus pauses in another thought to have a seizure disorder. Thus, combined ambulatory EEG/ECG monitoring may prove useful in the evaluation of some patients with syncope.

Rate-modulated pacemakers.

Rate-modulated pacing is an advancement in pacing technology that has opened the way for the development of a wide variety of pacemaker generators and pacing modes. Rate-modulated pacemakers use a physiologic sensor other than the sinus node to adjust the pacing rate according to the physiologic needs of the patient. As rate-modulated pacemakers become more widely used, nurses caring for patients with these devices need to understand pacing physiology as well as rate-modulated pacing technology to provide optimal patient care.

Spontaneous changes in ventricular tachycardia cycle length.

Understanding spontaneous fluctuations in ventricular tachycardia cycle length is required to develop algorithms for ventricular tachycardia detection and termination. Variations in cycle length, time to stable cycle length and the range of RR intervals during ventricular tachycardia were analyzed in 74 episodes of sustained monomorphic ventricular tachycardia induced in patients not taking antiarrhythmic medication. Linear regression demonstrated cycle length variability to decrease over time (41 +/- 24 to 17 +/- 19 ms, p less than 0.001). Slower ventricular tachycardia had more cycle length variability than faster ventricular tachycardia (p less than 0.001). Ventricular tachycardia that was initially more variable tended to remain more variable (p less than 0.001). Fifty-four percent of episodes stabilized within the first 15 beats, 75% by 30 beats and 93% by 50 beats. The number of beats to stable cycle length was independent of ventricular tachycardia rate. The average range in cycle length per episode was 127 +/- 72 ms; 12% of ventricular tachycardia episodes varied by less than 50 ms and 45% by less than 150 ms. The maximal range in RR intervals from a single episode of ventricular tachycardia was 290 ms. Therefore, ventricular tachycardia demonstrates a wide range of cycle lengths and has time-dependent changes in variability and stability. These cycle length changes should be considered in the algorithms for ventricular tachycardia detection and termination by automatic antitachycardia devices.

Implementing a flow sheet for thrombolytic therapy.

Complete and accurate documentation is necessary for optimal nursing care of patients receiving thrombolytic therapy for acute myocardial infarction. A tool is necessary to facilitate smooth transition and consistent patient care in communication between the emergency department and coronary care unit. The authors have developed a simple flow sheet to be used at the bedside for a clinical research protocol involving thrombolytic therapy.

Pacemaker-mediated tachycardia from a single chamber temperature sensitive pacemaker.

This report describes a case of pacemaker-mediated tachycardia from a single chamber temperature sensitive rate modulated pacemaker. The patient experienced diaphragmatic pacing that produced an increase in right ventricular blood temperature. This temperature increase was sensed by the pacemaker and led to sustained upper rate limit pacing. Decreasing the ventricular output to prevent diaphragmatic capture eliminated further episodes of pacemaker-mediated tachycardia.