1/22. Fatal cardiac ischaemia associated with prolonged desflurane anaesthesia and administration of exogenous catecholamines.PURPOSE: Four cardiac ischaemic events are reported during and after prolonged anaesthesia with desflurane. CLINICAL FEATURES: We have evaluated desflurane in 21 consecutive patients undergoing advanced head and neck reconstructive surgery. Four deaths occurred which were associated with cardiac ischaemic syndromes either during or immediately after operation. All patients in the study received a similar anaesthetic. This comprised induction with propofol and maintenance with alfentanil and desflurane in oxygen-enriched air. Inotropic support (either dopamine or dobutamine in low dose, 5 micrograms.kg.min-1) was provided as part of the anaesthetic technique in all patients. Critical cardiovascular incidents were observed in each of the four patients during surgery. These were either sudden bradycardia or tachycardia associated with ST-segment electrocardiographic changes. The four patients who died had a documented past history of coronary heart disease and were classified American Society of Anesthesiologists (ASA) II or III. One patient (#2) did not survive anaesthesia and surgery and the three others died on the first, second and twelfth postoperative days. Enzyme increases (CK/CK-MB) were available in three patients and confirmed myocardial ischaemia. CONCLUSION: These cases represent an unexpected increase in the immediate postoperative mortality for these types of patients and this anaesthetic sequence.- - - - - - - - - - ranking = 1keywords = long (Clic here for more details about this article) |
2/22. Concealed conduction in the reentrant pathway as a mechanism of stable ventricular quadrigeminy.This is the first report on the stable occurrence of ventricular quadrigeminy as a manifestation of concealed bigeminy in a case of fixed and late coupled ventricular extrasystoles. A 46-year-old man is reported in whom the period of ventricular bigeminy alternated with the period of ventricular quadrigeminy. Coupling intervals of the extrasystoles were fixed and much longer than sinus QT intervals. When the heart rate is decreased, the period of bigeminy changed to the period of quadrigeminy without gradual decrease in coupling of the preceding extrasystoles. Once such a change occurred, stable quadrigeminy is maintained for a period. These findings suggest the possibility that concealed electrotonic conduction of blocked impulses and interference of conducted impulses may occur in the reentrant extrasystolic pathway as a mechanism of stable ventricular quadrigeminy.- - - - - - - - - - ranking = 0.2keywords = long (Clic here for more details about this article) |
3/22. The heart-brain connection.We have long known that patients with vascular disease in one system are at risk for vascular disease in other systems. Beyond this, we are recognizing the increased risk for cardiovascular patients to develop stroke not only as the result of arrhythmia, but also at the time of cardiovascular events or procedures. This presents clinical challenges to nurses with either neurological or cardiovascular expertise, requiring development of new awareness, clinical and critical thinking skills, and collaboration with their colleagues in other specialties. Three case studies illustrate patient presentations ranging from the subtle to the obvious. Pathophysiology of stroke is reviewed. Leading-edge management strategies and supporting literature highlight the benefits of prompt identification and management of the stroke patient. The stroke Watch Action Team (SWAT) has proved to be an effective means of expediting patient identification and access to effective stroke treatment.- - - - - - - - - - ranking = 0.2keywords = long (Clic here for more details about this article) |
4/22. Ventricular tachycardia induced by supraventricular extrasystoles.electrocardiography was performed in a newborn boy without organic heart disease, in whom supraventricular extrasystoles with varying coupling were seen. The supraventricular extrasystoles were occasionally followed by ventricular extrasystoles. The coupling intervals of ventricular extrasystoles to the preceding supraventricular extrasystoles were also considerably variable. Ventricular tachycardia occurred following comparatively late coupled ventricular extrasystoles. This is the first known report on ventricular tachycardia following comparatively late coupled ventricular extrasystoles in a newborn infant. This strengthens our previous suggestion that such ventricular tachycardia can be caused by longitudinal dissociation in the reentrant pathway of extrasystoles.- - - - - - - - - - ranking = 0.2keywords = long (Clic here for more details about this article) |
5/22. Electrophysiological characteristic of a patient exhibiting the short-coupled variant of torsade de pointes.A 41-year-old man was admitted because of syncope. The electrocardiogram showed torsade de pointes (Tdp) with no long QT interval and the coupling interval of the initial beat of Tdp was 240 ms. Heterogeneity of ventricular refractoriness was observed together with shortness of the effective refractory period measured at the right ventricular inflow site where the paced QRS morphology was the same as that of the initial beat of Tdp. verapamil could suppress frequent ventricular premature complexes with a short coupling interval, which lead to Tdp. Polymorphic ventricular tachycardia was induced by triple ventricular extrastimuli. A pure potassium channel blocker was successful in inhibiting polymorphic ventricular tachycardia inducibility by prolongation of refractoriness. These results suggested that triggered ventricular premature complexes may be represent the initiating mechanism, whereas the shortness of local refractory period and heterogeneity of ventricular refractoriness may play a role in the development and the maintenance of the Tdp.- - - - - - - - - - ranking = 0.4keywords = long (Clic here for more details about this article) |
6/22. Spontaneous cardiac resynchronization.A 73-year-old woman with dilated cardiomyopathy presented with heart failure. The ECG showed sinus rhythm with left bundle branch block, left-axis deviation and prolonged QRS duration and frequent ventricular premature complexes from the left ventricular septal wall were present. Ventricular premature beats had narrower QRS duration than sinus node beats conducted through the His-purkinje fibers consistent with resynchronizing beats. The mechanisms of narrowing of the QRS complex produced by premature beats in cases of impaired intra and interventricular conduction are discussed.- - - - - - - - - - ranking = 0.2keywords = long (Clic here for more details about this article) |
7/22. Masked complete atrioventricular block in a patient with ventricular preexcitation.A 45-year-old male with a preexcited QRS consistent with WPW syndrome was hospitalized for syncope. ECG monitoring revealed episodes of advanced atrioventricular block. An electrophysiologic study demonstrated right anteroseptal preexcitation and revealed an intermittent block in the accessory pathway and AV complete block causing long periods of spontaneous asystole. A DDD pacemaker was implanted without ablation of the accessory pathway.- - - - - - - - - - ranking = 0.2keywords = long (Clic here for more details about this article) |
8/22. Rate-dependent QRS prolongation during exercise testing associated with hyperkalemia.The present case showed gradual increase of QRS duration from 100 ms up to 180 msec during an ergometer exercise test along with the heart rate increase. After exercise, QRS duration shortened and normalized. Laboratory test showed hyperkalemia (K = 8.0 mEq/l). T1 myocardial scintigraphy revealed exercise-induced transient ischemia in posterolateral region of left ventricle. coronary angiography showed significant stenosis in the distal portion of left circumflex coronary artery. The increase of QRS duration was possibly due to the combination of hyperkalemia and the effect of mexiletine. The rate dependent blocking effect on sodium channel of mexiletine might be intensified under hyperkalemia.- - - - - - - - - - ranking = 1keywords = long (Clic here for more details about this article) |
9/22. Premature ventricular contraction-induced concealed mechanical bradycardia and dilated cardiomyopathy:.Left ventricular (LV) dysfunction due to frequent isolated premature ventricular contractions (PVCs) has been rarely reported. LV dysfunction and concealed mechanical bradycardia resolved in a patient with idiopathic dilated cardiomyopathy after the focal source of PVCs in the LV was eliminated by radiofrequency ablation (RFA). The patient remained free from PVCs and maintained normal LV function over 36-month follow-up. In a subset of patients with idiopathic dilated cardiomyopathy with frequent isolated PVCs, RFA of the arrhythmic focus restores normal LV function that can be long lasting.- - - - - - - - - - ranking = 0.2keywords = long (Clic here for more details about this article) |
10/22. Ventricular arrhythmia following short-acting nifedipine administration.Short-acting nifedipine is still advocated for use in children with severe hypertension, but is no longer recommended for use in adults because of adverse effects from rapid blood pressure reduction. A 19 year-old adolescent with symptomatic, severe hypertension (blood pressure 180/120) received 10 mg of short-acting nifedipine sublingually for blood pressure reduction. Within minutes after the dose, the patient complained of palpitations. tachycardia (heart rate 100 beats per minute) and bigeminy were noted on the cardiac monitor. The bigeminy resolved but premature ventricular contractions were noted for the duration of her hospital stay. We hypothesize that reflex sympathetic activation following an abrupt drop in blood pressure may cause arrhythmias because of elevated catecholamine levels. Given this, it may be more appropriate to treat severe hypertension in children with intravenous antihypertensive agents that can be titrated to produce controlled reductions in blood pressure.- - - - - - - - - - ranking = 0.2keywords = long (Clic here for more details about this article) |
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