Comparison of diltiazem at two dose levels with propranolol for treatment of stable angina pectoris

Two dose levels of diltiazem with propranolol were compared in the management of chronic stable angina. Two groups of patients were treated for alternate periods of 4 weeks with each drug in a double-blind crossover with computer-assisted maximal treadmill tests and ambulatory ST-segment monitoring for evaluation of efficacy and safety. In 12 patients who received diltiazem, 180 mg/day, the time to development of angina increased from 5.9 +/- 0.7 minutes (+/- standard error of the mean) during placebo treatment to 8.3 +/- 0.8 minutes during diltiazem treatment and to 9.2 +/- 0.8 minutes with propranolol, 240 mg/day. Three patients became angina-free when they were treated with both drugs. Among 12 patients who received diltiazem, 360 mg/day, 1 patient became angina-free during treatment with both drugs and 1 became angina-free with diltiazem only. The mean exercise time increased from 5.8 +/- 0.7 minutes with placebo to 8.6 +/- 1.0 minutes with diltiazem, 360 mg/day, and to 8.2 +/- 0.6 minutes with propranolol, 240 mg/day. Analysis of variance showed no difference in efficacy between the 2 doses of diltiazem or between the 2 drugs. Ambulatory heart rate was reduced both during the day and at night with both drugs and significantly more with propranolol than with diltiazem treatment. Except for 1 patient in whom a rash developed when given diltiazem, 180 mg/day, and another who had both a rash and first-degree heart block with diltiazem, 360 mg/day, both drugs were well tolerated. Thus, diltiazem in a daily dose of 180 or 360 mg/day is as effective as propranolol for the treatment of chronic stable angina.     

Determinants of sustained slow pathway conduction and relation to reentrant tachycardia in patients with dual atrioventricular nodal transmission

In 24 patients with dual atrioventricular (AV) nodal pathways, multiple incremental atrial pacing studies were performed to obtain atrial (A) to His (H) basic driven (A₁ and H₁) and extrastimulus (A₂ and H₂) intervals. Discontinuous A₁-A₂ and H₁-H₂ intervals were analyzed for relations between initial coupling times and subsequent A-H responses, and to examine curves of sequential paced cycle lengths (A-A intervals) versus A-H intervals. Seventeen patients showed sustained slow pathway (SP) conduction with demonstration of discontinuous A-A and A-H curves. Sustained SP conduction occurred at critical atrial paced rates when the first paced beat was blocked in the fast pathway (FP) with conduction via the SP. Eleven of these 17 patients had inducible sustained supraventricular tachycardia (SVT). A-H interval during SVT in these 11 patients was closely related to SP A-H interval during atrial pacing at the paced rate comparable to SVT rate (r = +0.89, p < 0.001). The seven remaining patients showed continuous A-A and A-H curves. In three of these seven patients, sustained SVT was inducible, suggesting ability to sustain SP conduction. All of these three patients had continuous A₁-A₂ and H₁-H₂ curves during sinus rhythm so that the first atrial paced beat could not be blocked in the FP for subsequent SP conduction. In the other four of the remaining seven patients, despite block of the first atrial paced beat in the FP with SP conduction, the second paced beat was blocked in the SP so that all subsequent beats resumed FP conduction. In conclusion, sustalned SP conduction in patients with dual AV nodal pathways requires (1) an initiating beat being blocked in the FP, (2) a critical rate cycle length, and (3) the ability of SP for repetitive conduction at critical rates.     

Influence of heart rate and atrial transport on left ventricular volume and function: relation to hemodynamic changes produced by supraventricular arrhythmia

The response of the left ventricle to pacing-induced changes in heart rate and the atrioventricular (A-V) relation was examined with equilibrium gated radionuclide ventriculography in 20 patients who had normal ventricular function after surgery for recurrent supraventricular tachycardia. In 10 patients count-derived left ventricular ejection fraction, end-diastolic volume and stroke volume were measured during sinus rhythm and during atrial pacing at 120, 140 and 160 beats/min. In the other 10 patients similar determinations were made during sequential A-V and simultaneous ventricular and atrial (V/A) pacing, both at rates of 100 and 160 beats/min. Left ventricular ejection fraction did not change significantly with atrial pacing (from 0.65 +/- 0.02 [mean +/- standard error of the mean] at a baseline sinus rate of 91 +/- 3 beats/min to 0.62 +/- 0.03 at 160 beats/min) despite a progressive decrease in end-diastolic volume. The percent reduction in end-diastolic volume (% delta EDV) and stroke volume (+ delta SV) from the baseline values was linear and related to change in heart rate (delta HR) as % delta EDV = -0.60 delta HR + 5.19 (r = 0.71; p less than 0.01) and % delta SV = -0.62 delta HR + 5.03 (r = 0.76; p less than 0.001). Left ventricular ejection fraction with baseline sequential A-V pacing at 100 beats/min was 0.67 +/- 0.03 and not significantly altered by either sequential A-V or simultaneous V/A pacing at 160 beats/min. At 100 beats/min, loss of atrial transport with simultaneous V/A pacing resulted in a small reduction in end-diastolic volume from a baseline value of -9.0 +/- 1.9 percent (p less than 0.01) and a nonsignificant reduction in stroke volume of -3.7 +/- 1.6 percent. During simultaneous V/A pacing at 160 beats/min, the reduction in end-diastolic and stroke volumes from the baseline value was -26.6 +/- 3.8 percent and -28.8 +/- 4.3 percent, respectively (both p less than 0.01), but was significantly smaller (-16.1 +/- 3.6 percent and -19.2 +/- 4.1 percent, respectively [p less than 0.05]) when atrial transport was maintained during sequential A-V pacing at the same heart rate. During simultaneous V/A pacing at 160 beats/min, two thirds of the reduction in end-diastolic and stroke volumes from the baseline value was due to the increment in heart rate as assessed from sequential A-V pacing and the other third was due to loss of atrial transport. The data indicate that the hemodynamic consequences of supraventricular tachyarrhythmias in patients with normal ventricular function are due primarily to decreases in ventricular volume as heart rate is increased and atrial contribution is lost rather than to any changes in left ventricular ejection fraction.     

Increase of microsomal glucose-6-phosphatase activity after chronic ethanol administration

To study the effect of chronic ethanol administration on the activity of hepatic microsomal glucose-6-phosphatase, female rats were pair-fed liquid diets with 36% of total calories either as ethanol or isocaloric carbohydrate (controls). The remainder of the diet contained 35% of total calories as fat, 18% as protein, and 11% as additional carbohydrate. Six weeks of ethanol feeding as isocaloric substitution for carbohydrate increased significantly the activity of glucose-6-phosphatase (expressed per mg microsomal protein) both in fed (38%; p < 0.001) and fasted 18%; p < 0.02) rats. When expressed per unit of body weight, the enzyme activity was increased even further both in fed (66%; p < 0.01) and fasted (43%; p < 0.01) rats. Another group of rats received diets containing 36% of calories either as ethanol or isocaloric fat. The remainder of the diet contained 11% of total calories as carbohydrate, 18% as protein, and 35% as additional fat. Six weeks of this ethanol feeding as isocaloric substitution for fat again increased glucose-6-phosphatase activity significantly. Ultracentrifugation in a Cs⁺-containing sucrose gradient to separate rough and smooth microsomes revealed that the increase in glucose-6-phosphatase activity after ethanol feeding occurred mainly in the smooth microsomal membranes.     

Efficacy of Single-Shot Adductor Canal Block Combined With Posterior Capsular Infiltration on Postoperative Pain and Functional Outcome After Total Knee Arthroplasty: A Prospective,Double-Blind,Randomized Controlled Study

BackgroundAdductor canal block (ACB) may preserve muscle strength and promote faster recovery than other methods of analgesia following total knee arthroplasty (TKA). However, there are contradictory reports on the efficacy of ACB. Here, we evaluated the efficacy of single-shot ACB combined with posterior capsular infiltration (PCI) vs multimodal periarticular infiltration analgesia in treating postoperative pain.MethodsThis study involved patients undergoing unilateral primary TKA at our institution from January 2018 to January 2019. Patients were randomized into 2 groups, one of which was treated with ACB combined with PCI, and the other with periarticular infiltration analgesia. Primary outcomes included postoperative pain as assessed by the visual analog scale (VAS) and consumption of morphine hydrochloride. The secondary outcome was functional recovery, as assessed by range of knee motion, quadriceps strength, and daily ambulation distance. Tertiary outcomes included the duration of hospital stay and postoperative adverse effects.ResultsPatients treated with ACB and PCI had lower resting VAS scores at 8 and 24 hours after surgery, and lower VAS scores during motion within 48 hours after surgery. Patients treated with ACB and PCI also consumed less morphine. There was no difference in functional recovery, duration of hospitalization, or incidence of adverse events.ConclusionThe ACB combined with PCI can reduce postoperative pain sooner after TKA without affecting postoperative functional recovery and increasing complications.     

Double ulnar osteomy for the treatment of congenital radial head dislocation

ObjectiveThe aim of this study was to retrospectively evaluate the effects of our double osteotomy technique in the treatment of congenital radial head dislocation (CRHD).MethodsA total 14 children (14 elbows; 71.42% male; mean age: 9.31 ± 3.06 years) with CRHD who underwent double osteotomy of the proximal ulna between April 2010 and June 2015 were included in the study. The patients with CRHD were identified according to medical history, plain radiographs or magnetic resonance imagings. The outcomes were evaluated through comparison of the preoperative and postoperative motion range of elbow and Mayo Elbow Performance Score (MEPS).ResultsAfter a follow-up of 13–35 months (22.29 ± 5.80), compared with pre-operation, the flexion (132.14 ± 3.23° vs 123.21 ± 7.75°, P = 0.003), extension (8.21 ± 4.21° vs 1.07 ± 3.50°, P = 0.003), and pronation of elbow (83.21 ± 4.21° vs 80.36 ± 4.14°, P = 0.011) improved significantly in all patients. Furthermore, the carrying angle was recovered to the normal level (5–15°) in all of these patients (18.57 ± 5.69° vs 8.21 ± 2.49°, P = 0.001). MEPS score was significantly increased postoperatively (96.79 ± 2.49 vs. 90.71 ± 1.82, P = 0.000), with the good outcome in CRHD patients.ConclusionThe results of our study suggested that this double osteotomy on the proximal ulna might be an effective method for the treatment of CRHD.Level of EvidenceLevel IV, Therapeutic Study.