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Biomedical subjects

C W Kong

Publications and source records attributed to C W Kong.

49 records · Page 3Linked to original sources
PubMed1989

Lack of effects of isosorbide-5-mononitrate on hepatic hemodynamics in HBsAg-positive cirrhosis.

We conducted a randomized controlled hemodynamic study to evaluate the effect of placebo and 20 mg isosorbide-5-mononitrate, a long-acting organic nitrate, in 19 patients with HBsAg-positive cirrhosis by the simultaneous measurement of portal venous pressure and wedged hepatic venous pressure. Baseline values for the two groups were similar. One hour after oral administration of 20 mg isosorbide-5-mononitrate in 10 patients, mean arterial pressure, mean pulmonary arterial pressure and pulmonary capillary wedge pressure significantly decreased from 92 +/- 13 (mean +/- S.D.) to 82 +/- 14 mmHg, from 12.9 +/- 4.5 to 9.3 +/- 2.4 mmHg and from 6.9 +/- 3.4 to 4.3 +/- 1.8 mmHg, respectively. However, both portal venous pressure gradient (from 18.1 +/- 3.6 to 17.5 +/- 3.0 mmHg) and hepatic venous pressure gradient (from 17.8 +/- 5.2 to 16.6 +/- 5.3 mmHg) remained unchanged during the study. In six patients who received 20 mg isosorbide-5-mononitrate twice daily for 7 days, hepatic venous pressure gradient remained unaltered as compared to basal and 1-hr values. There was no significant change in cardiac index, heart rate or systemic vascular resistance in either immediate (1-hr) or delayed (7-day) studies. Three patients (30%) developed mild headache or dizziness and two patients (20%) demonstrated systolic hypotension (less than mmHg) during the immediate study. This study shows that isosorbide-5-mononitrate appears to have no effect in treating portal hypertension in patients with HBsAg-positive cirrhosis. In addition, the isosorbide-5-mononitrate may affect the systemic circulation more than the portal circulation.

Aged↗
PubMed1989

The efficacy and safety of recombinant tissue plasminogen activator infusion in acute myocardial infarction.

UNLABELLED: Recombinant tissue plasminogen activator (rt-PA) is the most promising agent use for salvaging ischemic myocardium in acute infarction. To assess the safety and efficacy of rt-PA thrombolytic therapy, an open label clinical trial was conducted. Patients of acute myocardial infarction with angina, occurring within the five previous hours, was treated with rt-PA 100 mg infusion within three hours; followed with coronary arteriography to assess the patency rate of infarct vessels. Twenty-five cases of acute myocardial infarction were studied over a 10-month period. The patients, 24 male and one female, were aged 58.1 +/- 7.7 years. Rt-PA was given at 3.17 +/- 1.0 hour. Infarct-related vessels had opened in 21/24 cases when examined with coronary arteriogram three hours after infusion. Good antegrade flow of grade 2 to 3 was gained in 20/24 cases, representing an 83% success rate. One patient expired from cardiogenic shock during the infusion; another was expired from noncardiac accident after coronary bypass graft. The total inhospital mortality rate was about 8%. There was no major bleeding complication except in one case with gastrointestinal bleeding requiring transfusion. IN CONCLUSION: rt-PA is safe and effective in the treatment of acute myocardial infarction in the early stage. Coronary arteriography can be safely delayed until three hours postinfusion, and the achieved reperfusion rate is up to 83%.

Adult↗
PubMed1988

The influence of verapamil and nifedipine on hepatic indocyanine green clearance in patients with HBsAg-positive cirrhosis and ascites.

The influence of verapamil and nifedipine on hepatic indocyanine green kinetics was studied in 12 patients with HBsAg-positive cirrhosis and ascites. Hepatic clearance and its two biologic determinants, hepatic blood flow and metabolic activity (intrinsic clearance [maximum velocity/metabolite elimination rate constant, or Vmax/km]), were determined from hepatic indocyanine green elimination at steady state in patients with cirrhosis. Acute intravenous administration 10 mg verapamil significantly increased the hepatic indocyanine green blood flow (p less than 0.05), but significantly decreased the hepatic clearance (p less than 0.05), extraction ratio (p less than 0.05) and Vmax/km (p less than 0.05). However, acute sublingual administration of 10 mg nifedipine resulted in no significant change in any parameters of hepatic elimination function. These results show that verapamil, but not nifedipine, might impair the transhepatic extraction activity of hepatocytes in patients with HBsAg-positive cirrhosis and ascites.

Aged↗
PubMed1988

A noninvasive pre-atrial activity recording by signal averaging using esophageal electrode.

A noninvasive method employing the technique of signal averaging has been developed for recording sinoatrial (S-A) activity (pre-P wave). Recordings were obtained in man at the time of right heart catheterization. A bipolar esophageal electrode was utilized to record the prominent P waves that were used for triggering in the averaging process. After summing 150 beats, which had coefficients of correlation 0.97 or larger, deflections of small amplitude (less than 40 microV) were obtained preceding the atrial activity. Direct catheter recordings were also taken for comparison. With the new noninvasive method, the sinoatrial conduction time (SACT) estimated for patients with sick sinus syndrome (SSS) was 106 +/- 24 ms (101 +/- 20 ms for the same group measured directly). The SACT for healthy subjects used as the control group was 55 +/- 18 ms. There was good correlation between the pre-atrial activity recorded noninvasively by the esophageal electrode method and invasively from the direct catheter method. The linear correlation coefficient between these two techniques was 0.89 (P less than 0.001) in 17 patients.

Adult↗
PubMed1988

Effects of verapamil on estimated hepatic blood flow in patients with HBsAg-positive cirrhosis.

Acute and chronic effect of verapamil on estimated hepatic blood flow were investigated in 12 patients with HBsAg-positive cirrhosis and portal hypertension. Acute administration of verapamil results in a significant increase (8%) in estimated hepatic blood flow (p less than 0.05). However, after chronic continued administration of verapamil, the mean value of estimated hepatic blood flow remains unchanged vis-a-vis basal values. Acute and chronic use of verapamil significantly reduced the hepatic venous pressure gradient for about an average of 20% at 1 hr after drug administration (p less than 0.05) and 18% 2 weeks later (p less than 0.05). This drop was associated with a significant reduction in hepatic vascular resistance by 39% at 1 hr later and by 37% 2 weeks later. Furthermore, the drop in hepatic vascular resistance was independent of any verapamil-induced changes in systemic hemodynamics. Verapamil significantly increased the indocyanine green plasma clearance and extraction ratio after acute or chronic use of the drug. We conclude that in patients with HBsAg-positive cirrhosis, the mechanism of verapamil in reducing the hepatic venous pressure gradient is predominantly by inducing a drop in hepatic portal vascular resistance.

Hepatitis B Surface Antigens↗
PubMed1987

Endomyocardial fibrosis with massive endocardial calcific deposits.

Massive endocardial calcific deposits in the left ventricular chamber is such an uncommon lesion that only three cases have been reported previously. This report describes an apparently asymptomatic patient with endomyocardial fibrosis and massive endocardial calcific deposits. The results of electrocardiography, echocardiography, angiography, and endomyocardial biopsy findings are presented, and the pathogenesis of massive endocardial calcification is speculated upon. The interesting point is that the clinical history and manifestation of this patient suggests that endomyocardial fibrosis may occur in a benign form and long-term survival may be expected.

Biopsy↗
PubMed1987

Lack of effects of nifedipine on hepatic hemodynamics in patients with HBsAg-positive cirrhosis.

The acute effects of Nifedipine on hepatic venous pressure gradient (HVPG) and estimated hepatic blood flow (EHBF) were investigated in six patients with HBsAg-positive cirrhosis and portal hypertension by simultaneous hepatic venous catheterization. The mean arterial pressure significantly decreased by 18% at 1 h after sublingual administration of 10 mg Nifedipine. Significant increases in heart rate (13%) and cardiac output (20%) were also demonstrated in our patients 1 h after administration of Nifedipine. However, there were no significant changes in HVPG and EHBF after Nifedipine. We conclude that in patients with HBsAg-positive cirrhosis who receive Nifedipine, EHBF is maintained despite a substantial change in systemic hemodynamics, and that Nifedipine is not effective in acutely reducing HVPG.

Female↗
PubMed1986

Hemodynamic effect of propranolol on portal hypertension in patients with HBsAg-positive cirrhosis.

Wedged hepatic venous pressure, free hepatic venous pressure, and cardiac index were measured before and one hour after intravenous and one month after chronic oral administration of propranolol in nine patients with HBsAg-positive cirrhosis. The gradient between wedged hepatic venous pressure and free hepatic venous pressure was decreased 22.7% at one hour after intravenous administration of 5 mg propranolol, and a sustained decrease in hepatic venous pressure gradient was also demonstrated in five patients after one month of continuous oral administration of propranolol. Thus, we conclude that chronic oral administration of propranolol can reduce the hepatic venous pressure gradient in patients with compensated HBsAg-positive cirrhosis.

Adult↗
PubMed1984

The echocardiographic features of an aneurysm of the inter-atrial septum.

The echocardiographic features of a surgically confirmed case of an aneurysm of the inter-atrial septum presenting as a persistent right atrial lesion were described. The lesion appeared cystic and could be differentiated from solid tumours. In contrast to other reported cases of smaller aneurysms, the lesion in this patient remained in the right atrium and did not show any phasic variation during the respiratory cycle because of its larger size. A review of the reported echocardiographic features of intra-cavitary right atrial tumours and pseudotumours was made. This highlighted distinguishing features that could be used in the differential diagnosis of space-occupying lesion within the right atrium.

Adult↗
PubMedDate not supplied

The hemodynamic effect of verapamil on portal hypertension in patients with postnecrotic cirrhosis.

Wedged hepatic venous pressure, free hepatic venous pressure and cardiac index were measured before and 1 hr after i.v. administration as well as 1 month and 3 months after chronic oral administration of verapamil in 10 patients with HBsAg-positive cirrhosis. The gradient between wedged hepatic venous pressure and free hepatic venous pressure was decreased 14% at 1 hr after i.v. administration of 10 mg verapamil, and the sustained decrease in hepatic venous pressure gradient was also demonstrated in the patients after 1 month, and in six patients after 3 months of continuous oral administration of verapamil. The mean arterial pressure significantly decreased (p less than 0.01) 1 hr after the administration of verapamil. There was no significant change in other hemodynamic values. We conclude that chronic oral administration of verapamil can reduce the hepatic venous pressure gradient in patients with compensated HBsAg-positive cirrhosis and portal hypertension.

Adult↗
PubMedDate not supplied

Single-lead VDD pacemaker implantation via persistent left superior vena cava: an improved technique and a new modality.

Persistent left superior vena cava (PLSVC), which occurs in approximately 0.5% of the general population, may complicate pacemaker implantation by making lead insertion into the right ventricle more difficult and increasing lead instability when the transvenous approach is attempted. We describe our experience with four PLSVC patients with pacemakers. We developed an open J-loop technique in which the stylet tip is directed toward the orifice of the tricuspid valve anteroinferiorly. The lead was implanted into the right ventricular apex without difficulty. Three of our patients had high-degree atrioventricular block and received VVI pacemakers with the new technique. One patient with complete atrioventricular block received a single-lead VDD pacemaker by means of the same technique, with the paired electrodes positioned in the lower right atrium. Excellent results were obtained on exercise tolerance testing, 24-hour Holter monitoring, and echocardiographically determined systolic and diastolic function. This improved technique can simplify pacemaker implantation in patients with PLSVC. The VDD device is a new way to maintain systolic and diastolic function and is an appropriate option in patients with high-degree atrioventricular block and PLSVC who require pacemaker implantation.

Aged↗