Comparison of Isoproterenol Infusion and Nitrate Spray during Provocative Head-Up Tilt Test

BACKGROUND AND OBJECTIVES: The head-up tilt test (HUT) is widely used for the diagnosis of vasovagal syncope. To improve the sensitivity of the test, provocation with isoproterenol is frequently used. The aim of this study was to evaluate the values of isosorbide dinitrate spray as a provocation drug in the HUT. SUBJECTS AND METHODS: Two hundred patients, undergoing baseline HUT (60 degrees for 20 minutes) for suspected vasovagal syncope or presyncope and unexplained dizziness, were enrolled. If the baseline HUT was negative, isosorbide dinitrate (2.5 mg) spray was applied sublingually (group I, n=93), or isoproterenol (3 microgram/min) infused (group II, n=93), in a randomized fashion. The values of isosorbide dinitrate and isoproterenol were compared in those patients that developed a positive vasovagal response or who completed the drug-provocative HUT. RESULTS: Syncope was similarly reproduced in both groups (47.7 vs. 41.9%, p>0.05). Type I responses were most common in both groups, and types I and II responses were more common in group I than group II (78.0 vs. 55.6% and 12.2 vs. 5.6%, p<0.05, respectively). The average time to a positive response was longer in group I than group II (8.5+/-3.4 vs. 6.1+/-3.6 minutes, p<0.01). The sensitivity and specificity of the drug-provocative HUT were significantly higher in group I than group II (73.5 and 87.5% vs. 58.5 and 71.1%; respectively, p<0.01). The incidence of minor adverse effects were similar in both groups, but serious cardiac side effects were significantly more common in group II than group I (4.3 vs. 0%, p<0.05). CONCLUSION: Sublingual isosorbide dinitrate spray may be used as a simple, effective and well tolerated provocative drug during HUT.

A study on determinants of the inducibility and maintenance of atrial fibrillation / 대한내과학회지

BACKGROUND: Atrial fibrillation (AF) is thought to beget AF by shortening atrial refractoriness and reversal of rate adaptation of atrial refractoriness. This phenomenon of electrophysiologic remodeling of the atria during AF has been reported to play a major role in inducibility and stability of AF. METHODS: Thirty-one patients with induced AF lasting >1 second during electrophysiologic study for documented or suspected supraventricular or ventricular tachycardia were included in this study. All the patients had no structural heart disease and history of AF. High right atrium (HRA) burst pacing or extra-stimulation was applied to induce AF. Eleven patients with AF sustained >or=3 min was grouped into Group I and 20 patients with AF <3 min into Group II. P wave duration and amplitude, left atrial (LA) size, atrial refractory period (ARP), intraatrial conduction time (IACT) from HRA electrode catheter to His bundle electrode catheter and characteristics of atrial activities during induced AF were compared between 2 groups. RESULTS: There was no difference in the distribution of underlying cardiac arrhythmias. P wave durations and amplitudes and echocardiographic LA sizes were similar between 2 groups. ARPs and IACTs in group I and II were similar (198.0 +/- 23.9 ms vs. 200.8 +/- 23.0 ms; 38.7 +/- 8.5 ms vs. 38.6 +/- 9.5 ms, respectively). During AF, mean interval of atrial activities in group I was significantly shorter than group II (156.6 +/- 24.2 ms vs. 187.6 +/- 28.0 ms, p<0.01). The degree of irregularity of atrial activities during AF was significantly higher in group I than group II (16.9 +/- 8.7 vs. 9.8 +/- 5.0, p<0.05). The duration of the atrial activities was wider in group I than group II (81.4 +/- 17.5 ms vs. 53.9 +/- 12.4 ms, p<0.001) and the amplitude was lower in group I than group II (56.1 +/- 36.0% vs. 109.0 +/- 51.8%, p<0.05), and the degree of fractionation was greater in group I than group II (4.8 +/- 1.1 vs. 3.2 +/- 0.5, p<0.05). CONCLUSION: These results suggest that shortening of atrial refractoriness and lengthening of local conduction time at the time of or shortly after induction of AF may play a major role in the induction and stabilization of AF.

The Long-Term Clinical Outcomes of Low Molecular Weight Heparin Combined with Platelet Glycoprotein IIb/IIIa Inhibitor in Patients with Acute Coronary Syndrome

BACKGROUND AND OBJECTIVES: Platelet activation and aggregation, with resultant arterial thrombus formation, play pivotal roles in the pathophysiology of acute coronary syndrome (ACS). The efficacy of tirofiban, a specific inhibitor of the platelet glycoprotein IIb/IIIa receptor, combined with heparin, or low molecular heparin (LMWH), in the management of ACS were evaluated. SUBJECTS AND MEHTODS: One hundred seventeen patients (60.8+/-10.9 years, 76 male), with unstable angina or non-ST elevation myocardial infarction, who had ST-T changes and elevated troponin, were divided into 4 groups : Group I (n=30 : heparin alone), Group II (n=28 : LMWH, dalteparin alone), Group III (n=29 : tirofiban combined with heparin) and Group IV (n=30 : tirofiban with LMWH). The major adverse cardiac events (MACE) among the 4 groups, during 6-month clinical follow-ups, were compared. RESULTS: Percutaneous coronary intervention, or a coronary artery bypass graft, was performed in 23, 19, 19 and 22 patients from Groups I, II, III and IV, respectively (p=0.87). A minor bleeding complication developed in 2 (6.7%), 1 (3.6%), 1 (3.4%) and 2 patients (6.7%) in groups I, II, III and IV, respectively (p=0.79). During the six-month follow-up MACE occurred in 7 (30.4%), 6 (31.6%), 3 (15.8%) and 4 patients (18.2%) in groups I, II, III and IV, respectively (p=0.02 : Group I and II vs. Group III and IV). CONCLUSION: Tirofiban combined with LMWH is safe and may improve the long-term prognosis of patients with ACS.

A Case of Recurrent In-Stent Restenosis with Abundant Proteoglycan Component

A percutaneous coronary intervention (PCI) is known to be one of effective methods in the treatment of coronary artery disease. However, restenosis remains a major limitation to a PCI. Although neointimal cell proliferation is suspected to be the major cause of coronary stent restenosis, few histological characterizations of recurrent instent restenosis exist. We report a case of a 61-year-old man suffering from unstable angina due to secondary coronary in-stent restenosis in the proximal left anterior descending artery (LAD). An atherectomized tissue, obtained by a directional coronary atherectomy, showed myxoid tissue, characterized by a few stellate smooth muscle cells in the abundant extracellular matrix, which was blue-colored proteoglycan on modified Movat staining.

The Effect of Gender on Short- and Long-term Clinical Outcomes of Percutaneous Coronary Intervention in Korean Octogenarians

BACKGROUND AND OBJECTIVES: Previous studies examining the gender differences in patients undergoing percutaneous coronary intervention (PCI) have reported that women have a higher in-hospital mortality rate, and are at an increased risk for adverse outcomes compared to men. The aim of this study was to determine whether or not Korean women undergoing contemporary PCI have a higher risk than men. SUBJECTS AND METHODS:Seventy eight elderly patients with 105 lesions, including 33 women (47 lesions, 81.9+/-1.97 year-old) and 45 men (58 lesions, 81.6+/-1.74 year-old) who underwent PCI from Jan 1996 to Apr 2001 were enrolled in this study. The demographics, angiographic findings and the clinical outcomes of each gender were compared. RESULTS: Clinical diagnosis and risk factors for atherosclerosis for males and females were similar with the exception of their smoking status (36.7% vs. 14.8%, p=0.002) and stroke history (9.1% vs. 0%, p=0.038). There were no differences in the major in-hospital complications including cardiac death (12.1% vs 15.6%, p=0.75), acute myocardial infarction (AMI:3% vs. 0%, p=0.42), rescue PCI (3% vs. 0%, p=0.42) and emergent coronary artery bypass grafts (CABG:6.1% vs. 11.1%. p=0.44) between the two groups. A twelve-month clinical follow-up showed that the major adverse cardiac events including cardiac death (17.8% vs 28.9%, p=0.27), AMI (0% vs. 5.3%, p=0.5) and repeated revascularization (20.7% vs. 15.8%, p=0.6) in males and females were also similar. CONCLUSION: PCI in Korean female patients older than 80 years can be performed with a comparable procedural success rate and clinical outcomes to those of elderly male patients.