Effects of Pharmacological Autonomic Blockade on Dual Atrioventricular Nodal Pathways Physiology in Patients with Slow-Fast Atrioventricular Nodal Reentrant Tachycardia

The purpose of this study was to investigate the atrioventricular AV nodal physiology and the inducibility of AV nodal reentrant tachycardia (AVNRT) under pharmacological autonomic blockade (AB). Seventeen consecutive patients (6 men and 11 women, mean age 39 ± 17 years) with clinical recurrent slow-fast AVNRT received electrophysiological study before and after pharmacological AB with atropine (0.04 mg/kg) and propranolol (0.2 mg/kg). In baseline, all 17 patients could be induced with AVNRT, 5 were isoproterenol-dependent. After pharmacological AB, 12 (71 %) of 17 patients still demonstrated AV nodal duality. AVNRT became noninducible in 7 of 12 nonisoproterenol dependent patients and remained noninducible in all 5 isoproterenol dependent patients. The sinus cycle length (801 ± 105 ms vs 630 ± 80 ms, P < 0.005) and AV blocking cycle length (365 ± 64 ms vs 338 ± 61 ms, P < 0.005) became shorter after AB. The antegrade effective refractory period and functional refractory period of the fast pathway (369 ± 67 ms vs 305 ± 73 ms, P < 0.005; 408 ± 56 ms vs 350 ± 62 ms, P < 0.005) and the slow pathway (271 ± 30 ms vs 258 ± 27 ms, P < 0.01; 344 ± 60 ms vs 295 ± 50 ms, P < 0.005) likewise became significantly shortened. However, the ventriculoatrial blocking cycle length (349 ± 94 ms vs 326 ± 89 ms, NS) and effective refractory period of retrograde fast pathway (228 ± 38 ms vs 240 ± 80 ms, NS) remained unchanged after autonomic blockade. Pharmacological AB unveiling the intrinsic AV nodal physiology could result in the masking of AV nodal duality and the decreased inducibility of clinical AVNRT.     

Histological maturity of healed duodenal ulcer and ulcer recurrence after treatment with omeprazole or cimetidine

Abstract We investigated the relationship between histological maturity of healed duodenal ulcer and ulcer recurrence after treatment with omeprazole or cimetidine for 4 weeks. The healing rates, 92.5 and 72.4% in omeprazole-treated and cimetidine-treated groups, respectively, showed no significant difference between groups ( P > 0.05). Histologically, the regenerating mucosa of healed ulcer was divided into three categories: good, fair and poor patterns. Of the healed cases, 22 (59.5%) of 37 omeprazole-treated and 12 (28.6%) of 42 cimetidine-treated ulcers achieved a good pattern, showing significant difference between groups ( P = 0.01). The recurrence rate at 3 months showed statistically significant difference ( P < 0.05) between two groups: 5.4% in omeprazole-treated and 23.8% in cimetidine-treated patients. During the period between 3 and 6 months after healing, the difference in recurrence rate between omeprazole-treated and cimetidine-treated groups was statistically not significant (12.5% and 25%, respectively, P > 0.05), though the cumulative recurrence rate at 6 months showed a significant difference between groups (17.6% vs 44.7%, P = 0.027). All the recurrent cases of both groups had a fair or poor pattern of regenerating mucosa. The difference in recurrence rate was statistically significant between the healed ulcers with a good pattern and that with a fair or poor patterns both at 3 months and between 3 and 6 months after healing ( P > 0.001 in each). We concluded that better histological maturity of regenerating mucosa may contribute to the lower early recurrence in omeprazole-treated cases than in cimetidine-treated cases.     

Gastric metaplasia of regenerating duodenal mucosa and deformity of duodenal bulb: A correlative study

The correlation between the presence and degree of gastric metaplasia of regenerating duodenal mucosa and the deformity of duodenal bulb was studied. Based on the endoscopically morphological patterns of bulb, the duodenal ulcers were divided into three types: type I, with a normal-shaped bulb; type II, with a mildly deformed bulb; and type III, with a markedly deformed bulb. A total of 159 patients with active duodenal ulcers were scheduled to be treated with H₂-receptor antagonists. Of these patients, 124 proved to have a healed duodenal ulcer 4 weeks after initial treatment upon follow-up endoscopic examinations. Two biopsies were taken from the centre of the ulcer scar when the ulcer was found to be healed for light microscopic study. Histologically, the degree of gastric metaplasia was divided into three grades: grades 0, 1 and 2. The results show that a healed duodenal ulcer with a normal-shaped bulb is not frequently accompanied by gastric metaplasia. However, a healed ulcer with a markedly deformed bulb has a high incidence and degree of gastric metaplasia, which may be easily colonized by Helicobacter pylori and thus develop an environment of easy recurrence. Therefore, a cycle of healing and recurrence may exist in patients with a duodenal ulcer and a markedly deformed bulb. Eradication of H. pylori may be the best way to break this cycle.     

Atrial Dissociation After Atrial Compartment Operation for Chronic Atrial Fibrillation in Mitral Valve Disease

Atrial dissociation with segmental atrial arrhythmia is an interesting electrophysiological phenomenon. It was rarely reported before to be caused by anatomical exit block after cardiac surgery. We report the case of a 28-year-old patient who developed atrial dissociation after a surgical method for correcting atrial fibrillation—atrial compartment operation. The segmental atrial flutter was first found by Doppler echocardiography and proved later by detailed intracardiac mapping.     

Surgical Catheter Ablation of Ventricular Tachycardia Using Left Thoracotomy in a Patient with Hindered Access to the Left Ventricle

We report the case of a patient presenting with incessant monomorphic ventricular tachycardia resistant to antiarrhythmic drugs, and in whom usual percutaneous vascular or pericardial access to the left ventricle was hindered by mechanical aortic and mitral prosthetic valves. Because an epicardial location was suspected by electrocardiogram features and because access to the target area through the coronary sinus was not possible, we decided to perform a surgically based radiofrequency (RF) ablation. Catheter mapping of the epicardial surface through surgical left lateral thoracotomy in the operating room confirmed the epicardial location of the arrhythmogenic substrate and allowed successful RF ablation of the clinically incessant tachycardia. Combined surgical and electrophysiological approach should therefore be performed when RF ablation is needed in case of unadvisable, difficult, or failed nonsurgical percutaneous access.     

Acute Post-Streptococcal Glomerulonephritis in Adults: A Long-Term Study

The long-term outcome after acute post-streptococcal glomerulonephritiswas studied in 57 patients (52 aged 16 or over) followed fora period of one to 14 years (mean seven years). All patientspresented with hypertension, haematuria and proteinuria. Theantistreptolysin 0 titre was raised or the serum complementwas low in all cases at the initial episode. All patients hadhistological evidence of a diffuse proliferative and exudativeglomerulonephritis at onset. Follow-up renal biopsy was performedin 33 patients; in 18 patients this was carried out five yearsor more after the initial illness. Five patients died beyondtwo years, only two having had abnormal renal function at thetime or death. Four patients were found to be mildly hypertensivewithout other clinical abnormalities. Eleven patients had proteinuria,haematuria or abnormal renal function; in three of these repeatrenal biopsy was normal, incomplete resolution was reportedin five, obsolescent glomeruli in one, and two others were notbiopsied. No patient who had normal renal function at the timeof follow-up had abnormal renal histology on biopsy. Obsolescentglomeruli were present in two other biopsies in associationwith evidence of incomplete resolution. It was concluded that the majority of patients with acute PSGNhave a good prognosis. Histological resolution of the renallesion may not occur for nine years.     

THE COMPOSITION OF VESICAL CALCULI

In January 1935, Dr. Branson kindly began to analyse samples of vesical cakuli at the request of Professor Digby. Dr. Khoo assisted in collecting the early records. In the latter half of 1933, Professor Digby suggested that the author should direct aad carry on the inves- tigation. After Dr. Branson went on leave, Dr. Jackson carried on th work of chemical analysis.