1/111. 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 = coronary (Clic here for more details about this article) |
2/111. Treatment of the bradycardia-tachycardia syndrome with permanent demand pacing.The bradycardia-tachycardia syndrome (paroxysmal supraventricular tachycardia alternating with sinus bradycardia and episodes of sinus node arrest) has previously presented a complicated therapeutic dilemma when excitatory and suppressive drugs have been utilized. A patient with this syndrome successfully treated with a permanent ventricular transvenous demand pacemaker is presented. Various aspects of this syndrome as well as facets of diagnosis and treatment have been reviewed and discussed. Significant underlying cardiac disease was ruled out in this patient by the usual diagnostic methods including left heart catheterization and coronary angiography. An interesting possibility of the relationship of vagal stimulation secondary to hiatus hernia as an etiologic factor in this syndrome has been discussed. The opinion is expressed that the currently preferred method of treatment is the insertion of a permanent transvenous pacemaker alone or in conjunction with antiarrhythmic drugs, preferably digitalis and propranolol.- - - - - - - - - - ranking = 1keywords = coronary (Clic here for more details about this article) |
3/111. Electrophysiological mechanisms of conversion of typical to atypical atrioventricular nodal reentrant tachycardia occurring after radiofrequency catheter ablation of the slow pathway.This report presents an adult patient with conversion of typical to atypical atrioventricular nodal reentrant tachycardia (AVNRT) after slow pathway ablation. Application of radiofrequency energy (3 times) in the posteroseptal region changed the pattern of the atrioventricular (AV) node conduction curve from discontinuous to continuous, but did not change the continuous retrograde conduction curve. After ablation of the slow pathway, atrial extrastimulation induced atypical AVNRT. During tachycardia, the earliest atrial activation site changed from the His bundle region to the coronary sinus ostium. One additional radiofrequency current applied 5 mm upward from the initial ablation site made atypical AVNRT noninducible. These findings suggest that the mechanism of atypical AVNRT after slow pathway ablation is antegrade fast pathway conduction along with retrograde conduction through another slow pathway connected with the ablated antegrade slow pathway at a distal site. The loss of concealed conduction over the antegrade slow pathway may play an important role in the initiation of atypical AVNRT after slow pathway ablation.- - - - - - - - - - ranking = 1keywords = coronary (Clic here for more details about this article) |
4/111. Recurrent ventricular tachycardia in hypothyroidism.Ventricular tachycardia associated with myxoedema is rare. Only two cases have so far been documented. In the report by Hansen, the patient had recurrent chest pain which suggested coexisting coronary heart disease. In the second case, the patient developed recurrent ventricular tachycardia only after intravenous triiodothyronine was given. This paper reports a further case of hypothyroidism with recurrent episodes of ventricular tachycardia and ventricular fibrillation which was not associated with any of the established causes of this arrhythmia.- - - - - - - - - - ranking = 1keywords = coronary (Clic here for more details about this article) |
5/111. Concealed accessory pathway with long conduction times and incremental properties: a case report.Concealed AP with Slow and Incremental Conduction. We report a peculiar form of permanent junctional reciprocating tachycardia that occurs only during daytime and physical activity. ECG obtained during tachycardia showed an unusual progressive shortening of the ventriculoatrial (VA) interval that was maximal at the first complex and shortest at the last one before block occurred, always at the accessory pathway level. This phenomenon has not been previously described and appears to be a reverse type of Wenckebach block. It was observed during salvos of spontaneous tachycardia and could be reproduced by right ventricular pacing. The accessory pathway was ablated successfully at the right posteroseptal region, close to the coronary sinus ostium. After ablation, there was no VA conduction, and tachycardia did not recur during a 9-month follow-up period.- - - - - - - - - - ranking = 1keywords = coronary (Clic here for more details about this article) |
6/111. Extensive myocardial stunning showing transient regression of prolonged T wave inversion and prolonged sympathetic denervation.A 69-year-old woman was admitted to the hospital with palpitations. Although left ventriculography showed extensive akinesis except in the basal hyperkinetic segment, coronary angiography showed normal coronary arteries. 123I-metaiodobenzylguanidine (MIBG) accumulation was obviously reduced in the anteroseptal, apical and inferior areas. Inverted T waves developed on day 3 and disappeared on day 104 after transient regression. echocardiography showed normal left ventricular motion two weeks later. ergonovine provocation test showed no vasospasm and thallium-201 showed no perfusion defect on day 46. electrocardiography and MIBG returned to normal on day 216. These findings suggest prolonged sympathetic nerve injury in extensive myocardial stunning.- - - - - - - - - - ranking = 2keywords = coronary (Clic here for more details about this article) |
7/111. coronary sinus pacing in an elderly patient with Bjork-Shiley tricuspid valve replacement.We report the first case of permanent pacing via the coronary sinus in a patient with a Bjork-Shiley tricuspid valve replacement. This may be the route of choice in this group of patients.- - - - - - - - - - ranking = 1keywords = coronary (Clic here for more details about this article) |
8/111. Permanent left atrial tachycardia: radiofrequency catheter ablation through the coronary sinus.The case of a 13-year-old child with an unusually localized "focal" permanent atrial tachycardia is reported. Electrophysiologic study showed that the earliest atrial activation occurred in the distal coronary sinus and preceded the atrial depolarization recorded along the endocardial side of the lateral part of the mitral annulus. Distal coronary sinus mapping revealed a fragmented, polyphasic atrial electrogram. Radiofrequency current delivery to the site permanently stopped the tachycardia.- - - - - - - - - - ranking = 6keywords = coronary (Clic here for more details about this article) |
9/111. Left ventricular outflow tract tachycardia originating from the right coronary cusp: identification of location of origin by endocardial noncontact activation mapping from the right ventricular outflow tract.Idiopathic left ventricular outflow tract (LVOT) tachycardia has been shown to originate from a supravalvular site in some patients. Considerable attention recently has focused on identifying this variant of LVOT tachycardia on 12-lead ECG. We report the case of 15-year-old boy in whom a noncontact three-dimensional mapping electrode deployed in the right ventricular outflow tract (RVOT) assisted in identifying a supravalvular LVOT tachycardia. observation of two early breakthrough sites in the RVOT and right ventricular septum suggested a right aortic cusp origin of the tachycardia. Pace mapping in the right aortic cusp identified a successful ablation site.- - - - - - - - - - ranking = 4keywords = coronary (Clic here for more details about this article) |
10/111. Effects of the pacing site on A-H conduction and refractoriness in patients with short P-R intervals.His bundle recordings were studied in four patients with short P-R and A-H intervals, and narrow QRS complexes, who had experienced several episodes of supraventricular tachyarrhythmias. The heart was paced from the high right atrium (HRA) and the coronary sinus (CS). In three patients the A-H Wenckebach phenomenon occurred at higher rates (greater than 200 pacing beats/min) when the CS was paced than when pacing was performed from the HRA. Moreover, CS stimulation produced smaller increments in the A-H interval than did pacing from HRA. The extrastimulus method of testing was done. In cases 1 and 2 the functional refractory period of the A-H tissues was 15 to 25 msec shorter during CS pacing than when pacing from the HRA. In case 3, the low right atrium (LRA) as well as the other two sites were paced. A type 1 gap was seen from HRA, a type 2 gap from CS, and both types appeared when the LRA was paced. Case 4, in which the mid-right atrium (MRA) was also stimulated, had a double pathway from HRA and CS with conduction through the accessory pathway late in the cycle and through the A-V node earlier in the cycle. However, the A-V node could not be penetrated during MRA stimulation. It appeared that the pacing site influenced the A-H conduction pattern and refractoriness, possibly by changing the site and/or mode of entry of the stimulus into the pathways that are responsible for this syndrome.- - - - - - - - - - ranking = 1keywords = coronary (Clic here for more details about this article) |
| | Next -> |