Is cardiovascular disease more common in Vietnam veterans exposed to agent orange? / 대한내과학회지

BACKGROUND: TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin), a material of agent orange, was reported as a deadly poison in spite of its presence at extremely small doses. It has been reported that TCDD can cause various kinds of cancers and harmful effects on humans. However, a correlation between exposure to TCDD and cardiovascular disease is not yet known. Thus, we intended to examine the correlation between TCDD exposure and cardiovascular disease through an analysis of coronary angiograms in veterans of the Vietnam War. METHODS: A consecutive 115 patients undergoing coronary angiograms between April 2004 and June 2005 at Gwangju Veterans Hospital were analyzed. The patients were divided into two groups: 57 patients exposed to TCDD (Group I, average age 59.2+/-4.2 years) and 58 patients that were not exposed to TCDD (Group II, Average age 60.1+/-5.6 years). The clinical and coronary angiographic findings were evaluated. RESULTS: Baseline clinical characteristics, inflammatory markers and echocardiographic parameters were not different between patients in the two groups. The incidence of diabetes (43.9% vs. 25.0%, p=0.035) and hyperlipidemia (47.4% vs. 27.6%, p=0.028) were higher in group I patients than group II patients. Significant coronary artery stenosis was more common in group I (45 cases, 78.9%) thanin group II (33 cases, 56.9%) (p=0.011). CONCLUSIONS: There was a higher incidence of diabetes, hyperlipidemia, and significant coronary artery stenosis in patients that underwent a diagnostic coronary angiogram that were previously exposed to TCDD.

The Clinical Effects of Abciximab Combined with Dalteparin for High-Risk Percutaneous Coronary Intervention in Patients with Acute Myocardial Infarction

BACKGROUND AND OBJECTIVES: The therapeutic efficacy of combined platelet glycoprotein IIb/IIIa receptor blocker with low molecular weight heparin (LMWH) is unknown for patients with acute myocardial infarction (AMI) and who underwent percutaneous coronary intervention (PCI). SUBJECTS AND METHODS: A total of 140 patients with AMI and who underwent high-risk PCI was divided into two groups: UFH (group I: 70 patients, 58.7+/-10.5 years of age), and dalteparin (group II: 70 patients, 59.6+/-9.8 years of age). The major adverse cardiac events (MACE) during hospitalization and during the 4 years after PCI were evaluated. RESULTS: The baseline clinical characteristics and angiographic characteristics were not different between the two groups. There were 62.9% totally occluded lesions with thrombus in both groups. Procedural success was achieved for 91.4% of the group I patients and for 90.0% of the group II patients. Any bleeding and hemorrhagic events were not different between the two groups. No significant intracranial bleeding was observed in both groups. The number of in-hospital MACEs was 7 (10.0%) in group I and 4 (5.7%) in group II. Four-year clinical follow-up was performed for 97% of the patients. As a result of the MACEs during the 4 years after PCI, death occurred in 6 (8.6%) patients in group I and in 7 (10.0%) patients in group II. Myocardial infarction occurred in 4 (5.7%) and 4 (5.7%) patients, respectively, target vessel revascularizations were done in 23 (32.9%) and 16 (22.9%) patients, respectively, and coronary artery bypass surgery was done in 3 (4.3%) and 1 (1.4%) patients, respectively. Overall, MACEs occurred in 33 (47.1%) patients of group I and in 26 (35.1%) patients of group II during the 4-year clinical follow-up (p=0.23). CONCLUSION: The long-term clinical outcome of dalteparin combined with abciximab is comparable with that of UFH plus abciximab for the high risk patients with AMI who receive PCI.

A successful stenting of the coarctation of aorta in a patient with acute pulmonary edema / 대한내과학회지

Coarctation of aorta is a rare vascular disorder which is one of causes of secondary hypertension. Since the early 1990s stenting in the coarctation of aorta has been introduced as an alternative treatment method, there were a few cases which were treated by stent implantation for the coarctation of the aorta in Korea. But the case which was treated using stent in congestive heart failure with pulmonary edema has never been reported. We report on successful management of a 64-year-old female patient, who presented with acute heart failure and pulmonary edema due to severe aortic coarctation. After endotracheal intubation, aortogram was performed, which revealed a severe narrowing in the distal thoracic aorta with a peak systolic pressure gradient of 100 mmHg across the lesion. Stent implantation was performed with 24x100 mm self-expandable Nitinol-S stent after predilation with 10x40 mm balloon. After stenting, patient's symptom and sign of congestive heart failure were remarkably improved and endotracheal intubation tube was able to be removed. And no significant adverse cardiac events observed during a nine-month clinical follow-up.

The Effects of QRS Duration and Pacing Sites on the Acute Hemodynamic Changes during Right Ventricular Pacing

BACKGROUND: Has been reported that patients exhibiting prolonged paced QRS duration tend to have more serious heart disease, and the paced QRS duration can be an effective indicator of impaired left ventricular function. However, the acute and chronic hemodynamic effects of paced QRS duration and pacing sites during right ventricular (RV) pacing remain unknown. METHODS: A total of 14 patients who underwent electrophysiologic study for paroxysmal supraventricular tachycardia were examined. RV pacing was performed at 10 different sites with cycle lengths of 600 ms and 500 ms utilizing a 6-7F deflectable quadripolar electrode catheter. Systolic, diastolic, and mean blood pressures during pacing were measured once the blood pressure was stabilized. RESULTS: During RV pacing, blood pressures (systolic/diastolic/mean) decreased. The change of post-pacing QRS duration and pre-pacing the systolic blood pressure (SBP) were greater in the group with paced QRS duration. The differences overall were greater than 140 ms. The SBP decrease during pacing was larger in the group exhibiting paced QRS duration of greater than 140 ms. The SBP decrease during pacing showed relation to QRS duration during pacing (r=0.500, p=0.001), the change of QRS duration post-pacing (r=0.426, p=0.001), and SBP during sinus rhythm (r=0.342, p=0.001) on linear correlation analysis. The pacing site, on the other hand, did not affect acute hemodynamic changes during pacing. CONCLUSION: Ventricular pacing of less than 40 ms at the area of paced QRS duration is recommended.

The Anticancer Effect and Mechanism of Photodynamic Therapy Using 9-Hydroxypheophorbide-alpha and 630 nm Diode Laser on Heterotransplanted Squamous Cell Carcinoma of Head and Neck / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The 9-Hydroxypheophorbide-alpha(9-HpbD-alpha) is a new photosensitizer, derived from a plant in water. We conducted a series of experiments in vivo to evaluate the anticancer effect and mechanism of photodynamic therapy using 9-HpbD-alpha and 630 nm diode laser on squamous cell carcinoma. MATERIALS AND METHOD: SNU-1041 cell line was heterotransplanted into the subcutaneous space of nude mouse. When the tumors grew up to 400 mm3, the animals were randomly seperated into 4 groups: Group I (n=5) of the normal control group;Group II (n=10), which received interstitial injection of 0.007 microgram/mm3 of 9-HpbD-alpha;Group III (n=10), which received irradiation with 1.6 J/mm3 of light using diode laser;Group IV (n=10), which received interstitial injection of 0.007 microgram/mm3 of 9-HpbD-alpha followed by irradiation with 1.6 J/mm3 of light 6 hours after the injection. After photodynamic therapy (PDT), tumor tissue was harvested for histopathologic study under light microscopy and transmission electron microscope (TEM). RESULTS: PDT group (Group IV) showed significant remission rate (70 %), compared to control group (p<0.05). The microscopic findings of the tumor section were characterized by massive necrosis and some apoptotic cells among the normal cells. TEM showed different morphologic changes between necrotic and apoptotic cells. These findings were considered as the evidence of direct cytotoxicity of PDT using 9-HpbD-alpha and 630 nm diode laser. CONCLUSION: The results suggest that therapy using PDT, 9-HpbD-alpha and diode laser shows an anticancer effect. Its therapeutic mechanism appears to be based on necrosis that is caused by direct cytotoxicity.

The effects of TIMI flow before mechanical reperfusion therapy on the long term clinical outcomes in patients with acute ST-segment elevation myocardial infarction / 대한내과학회지

BACKGROUND: Epicardial infarct-related artery patency is reliably assessed by the Thrombolysis In Myocardial Infarction flow grade (TFG), and this index is associated with clinical outcomes after fibrinolytics or primary angioplasty in patients with acute myocardial infarction (AMI). The aim of this study was to examine long-term clinical outcomes according to the pre-procedural TFG in AMI after percutaneous coronary intervention (PCI). METHODS: A total of 132 patients with AMI who underwent PCI between July 2001 and December 2001 at Chonnam National University Hospital were divided into two groups according to the pre-procedural TFG: Group I (n=60, 62.7+/-9.2 years, male 66.7%) with TFG 0-1 and Group II (n=72, 61.6+/-11.1 years, male 68.1%) with TFG 2-3. RESULTS: Hypertension was more prevalent in Group I than that in Group II (56.7% vs. 27.8%, p=0.001) and cardiogenic shock on admission was more frequently observed in Group I than that in Group II (20.0% vs. 5.6%, p=0.011). The left ventricular ejection fraction was lower in Group I than that in Group II (42.6+/-10.5% vs. 50.5+/-12.1%, p=0.022). The levels of inflammatory markers such as C-reactive protein (CRP), erythrocyte sedimentation rate, fibrinogen, white blood cell and monocyte counts were higher in Group I than in Group II. On diagnostic coronary angiogram, complex lesion was more frequently observed in Group I than that in Group II (53.4% vs. 36.2%, por=0.5 mg/dL, age >or=70 years, triple vessel disease, low pre-interventional TFG (0-1) and post-interventional TFG (0-2). CONCLUSION: Low pre-procedural TFG is associated with hypertension, cardiogenic shock, left ventricular dysfunction, and high mortality, and low event-free survival during one-year clinical follow-up after PCI in AMI.

The effects of QRS duration and pacing sites on the acute hemodynamic change during right ventricular pacing / 대한내과학회지

BACKGROUND: Intraventricular conduction disturbances, as manifested by increased QRS duration, are common in patients with advanced left ventricular (LV) dysfunction and adversely affect LV systolic and diastolic function. It has been reported that the patients with prolonged paced QRS duration have more serious heart disease, and the paced QRS duration can be a useful indicator of impaired LV function. Hemodynamic effects of paced QRS duration and pacing site during right ventricular (RV) pacing are unknown. METHODS: A total of 14 patients who underwent electrophysiologic study for paroxysmal supraventricular tachycardia at Chonnam National University Hospital were examined. All the patients had no structural heart disease. RV pacing was performed at 10 different sites with cycle length of 600 ms and 500 ms using a 6-7F deflectable quadripolar electrode catheter (Livewire, St. Jude Medical, Minneapolis, MN, USA). Systolic, diastolic, and mean blood pressures were measured after stabilization of blood pressure during pacing. RESULTS: Blood pressures (systolic/diastolic/mean) decreased from 146 +/- 31/95 +/- 28/125 +/- 23 mmHg to 128 +/- 33/80 +/- 25/107 +/- 20 mmHg, respectively. The change of QRS duration during pacing and the systolic blood pressure (SBP) before pacing were higher in the group with paced QRS duration greater than 140 msec (59.1 +/- 13.6 msec vs 84.9 +/- 18.7 msec, 141 +/- 30 mmHg vs 152 +/- 38 mmHg, p<0.001, p=0.011, respectively). The decrease of SBP during pacing was higher in the group with paced QRS duration greater than 140 msec (13 +/- 11 mmHg vs 24 +/- 14 mmHg, p=0.009). The decrease of SBP during pacing was related with QRS duration during pacing (r=0.500, p=0.001), the change of QRS duration during pacing (r=0.426, p=0.001), and SBP during sinus rhythm (r=0.342, p=0.001) on linear correlation analysis. Pacing site, however, did not affect acute hemodynamic change during pacing. The independent factors associated with the decrease of SBP during pacing were SBP before pacing and QRS duration during pacing. CONCLUSION: We concluded that acute deleterious hemodynamic effects of RV pacing are related with paced QRS duration but not with pacing site. Ventricuar pacing at the area of paced QRS duration less than 140 msec is recommended particularly in high risk patients.

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.

Clinical Characteristics of Hypervagotonic Sinus Node Dysfunction

BACKGROUND: Sinus node dysfunction (SND) is caused not only by intrinsic sinus node disease, but also by the extrinsic factors. Among the extrinsic factors, autonomic imbalance is most common. Symptomatic SND usually requires permanent pacemaker therapy. However, the clinical characteristics and patient response to medical therapy for hypervagotonic SND have not been properly clarified. MATERIALS AND METHODS: Thirty two patients (14 men, 18 women, 51 +/- 14 years) with hypervagotonic SND were included in this study, but those patients who had taken calcium antagonists, beta-blockers or other antiarrhythmic drugs were excluded. Hypervagotonic SND was diagnosed if the abnormal electrophysiologic properties of the sinus node were normalized after the administration of atropine (0.04 mg/kg). RESULTS: The presenting arrhythmias were 16 cases of sinus bradycardia (50.0%), 12 of sinus pause (37.5%), 3 of sinoatrial block (9.4%) and 1 of tachy-bradycardia (3.1%). Nine (28.1%) patients had hypertension, 7 (21.9%) smoked, 2 (6.3%) had diabetes mellitus, and 1 (3.1%) had hypercholesterolemia. Among the patients, 3 had no remarkable symptoms, 13 had dizziness, 7 had syncope, 3 had weakness and 6 had shortness of breath. Twenty five (78.1%) patients were treated with theophylline, 1 patient with tachy-bradycardia syndrome was treated with digoxin and propafenone, and 6 (18.8%) were treated with no medication. During the 43 +/- 28 month follow-up, 25 patients remained asymptomatic, but 6 who took no medication developed mild dizziness. One patient needed permanent pacemaker implantation owing to recurrent syncope despite of theophylline treatment. CONCLUSION: These results show that hypervagotonic SND has a benign course and most of the patients can be managed safely without implanting a pacemaker. (Ed note: I like the abstract. It is short and direct, as it should be.)

The prognostic significance of statin therapy in acute myocardial infarction patients with left ventricular dysfunction / 대한내과학회지

BACKGROUND: Statins reduce mortality of patients with coronary artery disease. However, many trials have excluded patients with ischemic heart failure. Statins may have other beneficial effects besides cholesterol lowering, such as anti-inflammatory properties and improvement of endothelial function. The aim of this study was to determine the effects of statin therapy in acute myocardial infarction (AMI) patients with left ventricular (LV) dysfunction. METHODS: We studied 202 patients with AMI with LV dysfunction [ejection fraction (EF) below 40%] between January 2001 and June 2002. The patients were divided into two groups: Group I (n=106, 60.8 +/- 10.3 years, male 71.7%) who were treated with simvastatin and Group II (n=96, 60.9 +/- 10.4 years, male 78.1%) who were not treated with simvastatin. RESULTS: At six-month after percutaneous coronary intervention (PCI), LVEF was more improved in Group I than in Group II (30.8 +/- 10.0% to 42.4 +/- 10.7% vs 31.9% to 38.9%, p=0.042). The levels of total cholesterol, triglyceride and low density lipoprotein-cholesterol were more decreased and the level of high density lipoprotein-cholesterol was more increased in Group I than in Group II. The levels of C-reactive protein, fibrinogen, white blood cell and monocyte count were more decreased in Group I than in Group II. During one-year clinical follow-up, statin therapy was associated with a significant reduction in mortality (1.9% vs 7.5%, p=0.048), restenosis rate (25.7% vs 43.1%, p=0.033) and repeat PCI rate (25.7% vs 43.1%, p=0.033). The event-free survival rate was higher in Group I than in Group II (79.8% vs 57.0%, p=0.001). CONCLUSION: Statin therapy improves LV systolic function and decreases mortality, restenosis and repeat PCI in the AMI with LV dysfunction.