A transthoracic echocardiographic follow-up study after catheter ablation of atrial fibrillation: can we detect pulmonary vein stenosis by transthoracic echocardiography?

BACKGROUND AND OBJECTIVES: While pulmonary vein isolation (PVI) is an effective curative procedure for patients with atrial fibrillation (AF), pulmonary vein (PV) stenosis is a potential complication which may lead to symptoms that are often unrecognized. The aim of this study was to compare differences between ablation sites in pulmonary venous flow (PVF) measured by transthoracic Doppler echocardiography (TTE) before and after PVI. SUBJECTS AND METHODS: ONE HUNDRED FIVE PATIENTS (M : F=64 : 41; mean age 56±10 years) with paroxysmal AF (n=78) or chronic, persistent AF (n=27) were enrolled. PVI strategies consisted of ostial ablation (n=75; OA group) and antral ablation using an electroanatomic mapping system (n=30; AA group). The ostial diameter was estimated by magnetic resonance imaging (MRI) in patients with PVF ≥110 cm/sec by TTE after PVI. RESULTS: No patient complained of PV stenosis-related symptoms. Changes in mean peak right PV systolic (-6.7±28.1 vs. 10.9±25.9 cm/sec, p=0.038) and diastolic (-4.1±17.0 vs. 9.9±25.9 cm/sec, p=0.021) flow velocities were lower in the AA group than in the OA group. Although the change in mean peak systolic flow velocity of the left PV before and after PVI in the AA group was significantly lower than the change in the OA group (-13.4±25.1 vs. 9.2±22.3 cm/sec, p=0.016), there was no difference in peak diastolic flow velocity. Two patients in the OA group had high PVF velocities (118 cm/sec and 133 cm/sec) on TTE, and their maximum PV stenoses measured by MRI were 62.5% and 50.0%, respectively. CONCLUSION: PV stenosis after PVI could be detected by TTE, and PVI by antral ablation using an electroanatomic mapping system might be safer and more useful for the prevention of PV stenosis.

The effect of cilostazol on stent thrombosis after drug-eluting stent implantation.

BACKGROUND AND OBJECTIVES: Placement of drug-eluting stents (DES) can be complicated by stent thrombosis; prophylactic antiplatelet therapy has been used to prevent such events. We evaluated the efficacy of cilostazol with regard to stent thrombosis as adjunctive antiplatelet therapy. SUBJECTS AND METHODS: A total of 1,315 patients (846 males, 469 females) were prospectively enrolled and analyzed for the frequency of stent thrombosis. Patients with known risk factors for stent thrombosis, except diabetes and acute coronary syndrome, were excluded from the study. All patients maintained antiplatelet therapy for at least six months. To evaluate the effects of cilostazol as another option for antiplatelet therapy, triple antiplatelet therapy (aspirin+clopidogrel+cilostazol, n=502) was compared to dual antiplatelet therapy (aspirin+clopidogrel, n=813). Six months after stent placement, all patients received only two antiplatelet drugs: treatment either with cilostazol+aspirin (cilostazol group) or clopidogrel+aspirin (clopidogrel group). There were 1,033 patients (396 in cilostazol group and 637 in clopidogrel group) that maintained antiplatelet therapy for at least 12 months and were included in this study. Stent thrombosis was defined and classified according to the definition reported by the Academic Research Consortium (ARC). RESULTS: defined and classified according to the definition reported by the Academic Research Consortium (ARC). RESULTS: During follow-up (561.7+/-251.4 days), 15 patients (1.14%) developed stent thrombosis between day 1 to day 657. Stent thrombosis occurred in seven patients (1.39%) on triple antiplatelet therapy and four patients (0.49%) on dual antiplatelet therapy (p=NS) within the first six months after stenting. Six months and later, after stent implantation, one patient (0.25%) developed stent thrombosis in the cilostazol group, and three (0.47%) in the clopidogrel group (p=NS). CONCLUSION: During the first six months after DES triple antiplatelet therapy may be more effective than dual antiplatelet therapy for the prevention of stent thrombosis. However, after the first six months, dual antiplatelet treatment, with aspirin and cilostazol, may have a better cost benefit ratio for the prevention of stent thrombosis.

Direct comparison of B-type natriuretic peptide and N-terminal pro-BNP for assessment of cardiac function in a large population of symptomatic patients.

BACKGROUNDS: B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NTproBNP) levels showed frequent discrepancies in individual patients. OBJECTIVES: The aims were 1) to compare the abilities of BNP and NTproBNP for the detection of left ventricular systolic dysfunction (LVSD) or diastolic dysfunction (LVDD) in the symptomatic patients, and 2) to assess the direct correlation and its independent determinants between them. METHODS: 1032 patients with dyspnea underwent BNP and NTproBNP measurements simultaneously. 967/1032 (93.7%) patients underwent echocardiography. Using the receiver operation characteristic curve analyses for the detection of LVSD (EF<45%) or advanced LVDD, the area under the curves (AUC) of both biomarkers was compared according to age, gender, body mass index (BMI), hemoglobin (Hb), and glomerular filtration rate (eGFR). Using multiple regression analysis, the direct correlation and its independent determinants were identified between them. RESULTS: In the entire population, the AUCs of BNP and NTproBNP had no significant differences (LVSD: 0.909 vs. 0.893, p=0.20; advanced LVDD: 0.897 vs. 0.879, p=0.13). In patients with BMI<25, the AUCs of BNP were significantly higher than those of NTproBNP (LVSD: 0.897 vs. 0.869, p=0.03; advanced LVDD: 0.916 vs. 0.885, p=0.02). They had strong correlation (r=0.895, p<0.001) and LVEF, eGFR<60 ml/min, Hb<12 g/dl and use of diuretics were the independent determinants between them. CONCLUSION: BNP and NTproBNP displayed strong correlation and near-identical performances for the screening of cardiac dysfunction. However, LVEF, renal function, Hb and use of diuretics should be considered for clinical interpretation.

Aortic Valve Sclerosis on Echocardiography is a Good Predictor of Coronary Artery Disease in Patients With an Inconclusive Treadmill Exercise Test.

BACKGROUND AND OBJECTIVES: The treadmill exercise test (TMT) is used as a first-line test for diagnosing coronary artery disease (CAD). However, the findings of a TMT can be inconclusive, such as incomplete or equivocal results. Aortic valve sclerosis (AVS) is known to be a good predictor of CAD. We determined the usefulness of assessing AVS on 2-dimensional (2D) echocardiography for making the diagnosis of CAD in patients with inconclusive results on a TMT. SUBJECTS AND METHODS: This prospective study involved 165 consecutive patients who underwent a TMT that resulted in inconclusive findings, 2D echocardiography to detect AVS, and coronary angiography to detect CAD. Following echocardiography, AVS was classified as none, mild, or severe. CAD was defined as >/=70% narrowing of the luminal diameter on coronary angiography. RESULTS: CAD was more common in patients with AVS than in patients without AVS (75% vs. 47%, respectively, p<0.01). Multiple logistic regression analysis showed that AVS was the only independent predictor of CAD {odds ratio=8.576; 95% confidence interval (CI), 3.739-19.672}. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the presence of AVS for predicting CAD in a patient with an inconclusive TMT were 62%, 67%, 64%, 75%, and 53%, respectively. During a 1-year clinical follow-up, patients with and without AVS were similar in terms of event-free survival rates. CONCLUSION: If the results of TMT for patients with chest pain on exertion are inconclusive, the presence of AVS on echocardiography is a good predictor of CAD.

Target organ status in white-coat hypertensives: usefulness of serum procollagen type I propeptide in the respect of left ventricular diastolic dysfunction.

BACKGROUND: Myocardial fibrosis is a feature of diastolic dysfunction and target organ damage, which was compared among subjects with normotension (NT), white-coat hypertension (WCH) and essential hypertension (EH). Serum procollagen type I propeptide (PIP) level was assessed as a marker of diastolic dysfunction in WCH. METHODS AND RESULTS: Of 90 subjects, 30 had NT and 30 had WCH (ambulatory daytime blood pressure <135/85 mmHg) and 30 had EH (untreated mild to moderate hypertension); all underwent biochemical and echocardiographic examinations. Those with WCH had a lower left ventricular (LV) mass index than those with EH, but it was higher than in the NT group. WCH patients had a lower mitral valve E/A ratio and a higher LV E/E' (E': septal mitral annular peak velocity) ratio than NT patients, whereas these values were higher and lower respectively than in the EH group. The LV E/E' ratio, an estimate of LV diastolic function, correlated with the serum PIP concentration in WCH patients (r=0.39, P=0.03). CONCLUSION: WCH is an intermediate group between NT and EH in respect of target organ damage. These results show a relationship between LV diastolic function and serum PIP in WCH, so the serum PIP level may be a useful marker of diastolic dysfunction and target organ damage in such patients.

Prognosis of large, symptomatic pericardial effusion treated by echo-guided percutaneous pericardiocentesis.

BACKGROUNDS: The causes and prognosis of pericardial effusion (PE) may be different according to time, region, economy, and hospital. This study was performed to evaluate the etiology, clinical outcome, and prognosis of patients with large, symptomatic PE treated by echo-guided pericardiocentesis at Kangnam St. Mary's Hospital (the Catholic University of Korea, Seoul, Korea). HYPOTHESIS: According to etiologies of large, symptomatic PE, the prognosis of patients may be different. METHODS: We reviewed 116 consecutive patients who underwent echo-guided pericardiocentesis due to large, symptomatic PE over the last 12 y. The Kaplan-Meier survival curve with log-rank method was applied for the survival analysis. RESULTS: Procedural success rate of echo-guided pericardiocentesis was 99.1%. Common causes of PE requiring pericardiocentesis were lung cancer (27.6%), tuberculosis (TB) (13.8%), and uremia (6.9%). The mortality rate of 6 mo after the pericardiocentesis was 80.3% in malignant PE, whereas the over-all mortality rate was 18.2% in nonmalignant PE (p < 0.0001). Among the malignant PE, lung cancer (27.6%) and breast cancers (6.9%) were the most common causes. The mean cytologic detection rate and mean life expectancy of malignant PE were 44% and 5-7 mo. Patients with breast cancer and lymphoma had relatively better life expectancy (11.4 and 7.7 mo), whereas those with stomach cancer and metastases of unknown origin (MUO) had poorer prognosis (1.2 and 2.3 mo). The most common causes of nonmalignant PE were TB, uremia, and iatrogenic, and their mean life expectancy was approximately 54 mo. CONCLUSIONS: Malignancy, especially lung cancer and TB, were the most common causes of large symptomatic PE. The prognosis of large symptomatic PE was related to the underlying disease. Malignant PE was associated with the poorest prognosis.

Takayasu's arteritis treated by percutaneous transluminal angioplasty with stenting in the descending aorta.

A 17-yr-old young woman was referred to our hospital with a 2-yr history of claudication of the lower extremities and severe arterial hypertension. Physical examination revealed significantly different blood pressures between both arms (160/92 and 180/95 mmHg) and legs (92/61 and 82/57 mmHg). The hematological and biochemical values were within their normal ranges, except for the increased erythrocyte sedimentation rate (83 mm/hr) and C-reactive protein (6.19 mg/L). On 3-dimensional computed tomographic angiography, the ascending aorta, the aortic arch and its branches, and the thoracic and, descending aorta, but not the renal artery, were shown to be stenotic. The diagnosis of type IIb Takayasu's arteritis was made according to the new angiographic classification of Takayasu's arteritis, Takayasu conference 1994. Percutaneous transluminal angioplasty with stenting was performed on the thoracic and abdominal aorta. After the interventional procedures, the upper extremity blood pressure improved from 162/101 mmHg to 132/85 mmHg, respectively. She has been free of claudication and there have been no cardiac events during 2-yr of clinical follow-up.

Coronary collaterals: the role of MCP-1 during the early phase of acute myocardial infarction.

BACKGROUND: The collateral growth (arteriogenesis) of an individual may vary from complete to absent during the early phase of acute myocardial infarction (AMI). However, the mechanisms underlying the large differences in the extent and adequacy of collateralization remain unclear. We hypothesized that shear stress-induced activation of monocyte chemoattractant protein-1 could potently contribute to the development of coronary collaterals during the early phase of AMI. METHODS: We enrolled forty patients with AMI who did not receive reperfusion therapy within 24 h after the onset of chest pain and who also underwent coronary angiography (CAG) from 1 to 7 days after admission (mean duration: 3.6+/-2.2 days). The grades of the collateral development were angiographically defined and grouped according to the grade of collaterals as absent (score 0, n=20) or well-developed (score 2, n=20) collateral circulation. The plasma concentrations of vascular endothelial growth factor (VEGF), endostatin, monocyte chemoattractant protein-1 (MCP-1), and stromal cell-derived factor-1 (SDF-1) were assessed by enzyme-linked immunosorbent assay and then these values were compared between the two groups. RESULTS: There were no differences in the demographic and angiographic characteristics except for the number of total occlusion in culprit lesion. The plasma MCP-1 levels were significantly higher in the group with well-developed collateral circulation compared to the group with absent collateral circulation (262+/-216 vs. 151+/-88 pg/ml, respectively, p=0.043). However, the plasma levels of VEGF, endostatin and SDF-1 were not different on comparisons between the groups (VEGF; 369+/-377 vs. 324+/-363 pg/ml, endostatin; 1.74+/-1.71 vs. 1.49+/-1.15 ng/ml, SDF-1; 1806+/-508 vs. 2091+/-772 pg/ml, respectively). CONCLUSION: During the early phase of AMI, the plasma levels of MCP-1 were significantly increased in the patients with well-developed collateral circulation as compared to those patients with absent collateral circulation. These findings suggested that the shear stress-induced overexpression of MCP-1 contributes significantly to the development of coronary collaterals during the early phase of AMI.

A close relationship between functional polymorphism in the promoter region of matrix metalloproteinase-9 and acute myocardial infarction.

OBJECTIVE: This study investigated whether the single nucleotide polymorphism (SNP) in the matrix metalloproteinase-9 (MMP-9) promoter (-1562C>T) is a significant risk factor for an acute myocardial infarction (AMI) and if SNPs affect the transcription of the gene that elevates the MMP-9 expression level. METHODS: A polymerase chain reaction, followed by a restriction fragment length polymorphism analysis, was performed in 173 control participants and 206 AMI patients. The serum levels of MMP-9 in the groups with or without the SNP were measured using ELISA and compared. RESULTS: There was a significantly higher incidence of th-1562C>T MMP-9 polymorphism in the AMI patients compared to the control group (27.6% vs 17.9%, p=0.04). A multiple logistic regression analysis of the risk factors for coronary artery disease and the MMP-9 polymorphism showed the MMP-9 polymorphism to be an important factor in the prediction of an AMI (odds ratio 1.67, 95% confidence interval 1.02-2.67, p=0.04). The serum level of MMP-9 was also higher in the group with the SNP than in the group without (494.8+/-3.66 ng/ml vs 309.5+/-2.19 ng/ml, p=0.04). CONCLUSION: These results suggest that the -1562C>T polymorphism in the MMP-9 promoter is strongly associated with an AMI.

A serial ultrasound assessment of neoaneurysm following paclitaxel-eluting stent implantation.

We present a case of serial regression of aneurysm of coronary artery complicating paclitaxel-eluting Taxus stent implantation in the mid anterior descending artery evaluated by intravascular ultrasound in a 55-year-old woman.

The relationship between the acute changes of the systolic blood pressure and the brachial-ankle pulse wave velocity.

BACKGROUND: The brachial-ankle pulse wave velocity (baPWV) is a useful parameter to assess arterial stiffness. However, it is difficult to evaluate arterial stiffness in hypertensive patients because the baPWV is affected by the blood pressure itself. This study was designed to estimate the relationship between the change of the blood pressure parameters and the baPWV (deltabaPWV) when hypertensive patients were subjected to an acute reduction of blood pressure. METHODS: Thirty patients with essential hypertension and whose blood pressure was higher than 140/90 mmHg were enrolled. In all the patients, the blood pressure and baPWV were measured using an automatic waveform analyzer with the patients at a resting state. When the reduction of blood pressure was more than 10 mmHg after sublingual administration of nifedipine 10 mg, then the blood pressure and baPWV were measured again in the same manner and then they were compared with the baseline values. Spearman's correlation and multiple linear regression tests were performed to estimate the relationship between the change of the blood pressure parameters (deltaSBP, deltaDBP, deltaMAP and deltaPP) and the deltabaPWV. RESULTS: The baPWV was significantly decreased shortly after the administration of nifedipine (1903.6+/-305.2 cm/sec vs. 1716+/-252.0 cm/sec, respectively, p<0.01). The deltabaPWV was correlated with the deltaSBP (r=0.550, p<0.01), deltaDBP (r=0.386, p<0.05), deltaMAP (r=0.441, p<0.05), and deltaPP (r=0.442. p<0.05). On the multiple regression analysis, the deltaSBP was the only significant variable for predicting the deltabaPWV, and the linear equation was deltabaPWV=8.7xSBP-48. CONCLUSIONS: The baPWV is affected by the systolic blood pressure level to a large degree and careful attention must be paid to the blood pressure level when evaluating arterial stiffness with using the baPWV.

Serum carboxy-terminal propeptide of type I procollagen (PIP) is a marker of diastolic dysfunction in patients with early type 2 diabetes mellitus.

This study was designed to investigate whether the serum concentration of the carboxy-terminal propeptide of procollagen type I (PIP), a marker of myocardial fibrosis, is related to changes of the ventricular filling dynamics in patients with early type 2 diabetes mellitus (T2DM). The T2DM group had lower mitral and tricuspid E/A ratios than the control group. Serum PIP was higher in patients with T2DM than in controls (131.1+/-45.6 vs. 109.3+/-32.5 ng/mL, p=0.039). A-Ar, an estimate of passive diastolic function, was inversely related to serum PIP levels in T2DM (r=-0.42, p=0.03). These results show a relation between LV diastolic function and serum PIP levels in early T2DM.

Clinical and angiographic characteristics of acute myocardial infarction caused by vasospastic angina without organic coronary heart disease.

BACKGROUND: Vasospastic angina (VA) can occasionally cause acute myocardial infarction (AMI). METHODS AND RESULTS: From January 2003 to June 2005, coronary spastic angina was diagnosed in 292 patients by performing spasm provocation tests. Among the 292 patients, 21 (7.2% of all the VA patients) had an AMI. There were 20 patients who initially visited the emergency room for AMI without suffering prior VA. One patient with a history of VA had an AMI when he discontinued his medication. Among the 21 VA patients with AMI, 14 had experienced severe emotional stress before they visited the emergency room. The spasm provocation test showed that the VA patients with AMI had more multivessel and diffuse spasm than the VA patients without AMI (p<0.001). CONCLUSION: Clinically, the VA patients with AMI usually had their first symptom of VA as the severe chest pain of AMI. Two-thirds of the VA patients with AMI had experienced emotional stress before their AMI. Angiographically, the spasm provocation test for VA patients with AMI showed more multivessel and diffuse spasm than in VA patients without AMI.

Noninvasive assessment of coronary vasodilating capacity using freehand 3-dimensional echocardiography with rotational scanning.

BACKGROUND: Noninvasive measurement of coronary vasomotion is important for the evaluation of patients with coronary artery disease (CAD). We tested the possibility of the assessment of epicardial coronary artery vasodilating capacity using freehand 3-dimensional (3D) echocardiography. METHODS: In 45 individuals (29 control subjects [age 51 +/- 12 years, male:female = 14:15; control group] with normal coronary angiogram and 16 patients with multivessel CAD ([age 60 +/- 12 years, male:female = 9:7; CAD group]), using a 3D echocardiography unit with magnetic tracking system linked to the conventional 2-dimensional ultrasound system, 3D echocardiography image acquisition and reconstruction of the distal left anterior descending coronary artery (LAD) flow were performed before and after sublingual nitroglycerin administration (0.6 mg). Quantitative analysis of coronary vasodilation was performed on cross-sectional 3D images and was compared with the mean diameter of the distal LAD by quantitative coronary angiography. RESULTS: The distal LAD diameter on coronary 3D increased from 2.28 +/- 0.79 to 3.32 +/- 1.07 mm (52.3 +/- 28.5%) in control group and from 2.36 +/- 0.65 to 2.89 +/- 0.81 mm (23.7 +/- 23.9%) in CAD group after nitroglycerin administration (P < .005 vs control group). The cut surface diameter of the 3D LAD flow was 2.17 +/- 0.34 mm and the mean diameter using quantitative coronary angiography was 1.99 +/- 0.28 mm. There was a good correlation between baseline diameter of 3D image and mean quantitative coronary angiography data (R = 0.673, P < .005). CONCLUSION: The vasodilation after nitroglycerin administration is reduced in advanced atherosclerosis and can be noninvasively measured. The 3D reconstruction of the distal LAD flow is a promising noninvasive technique to study coronary vasomotor function.

Relation between flow reserve capacity of penetrating intramyocardial coronary arteries and myocardial fibrosis in hypertension: study using transthoracic Doppler echocardiography.

OBJECTIVE: The purpose of this study was to compare coronary flow reserve (CFR) capacity of penetrating intramyocardial coronary artery (PICA) using transthoracic Doppler echocardiography and biochemical marker of myocardial fibrosis in hypertension (HTN). METHODS: In 58 patients (male:female ratio = 31:27; mean age 47 +/- 9 years) with chest pain and normal coronary angiogram findings, the width of color Doppler signal and peak diastolic velocity of PICA flow were measured in the myocardium just beneath the apical impulse window using transthoracic Doppler echocardiography. PICA-CFR and PICA-width ratio were calculated as the ratio of hyperemic to baseline peak diastolic velocity and as the ratio of hyperemic to baseline width after the adenosine infusion (140 mug/kg/min), respectively. Serum carboxy-terminal propeptide of procollagen type I, as a biochemical marker, was measured and patients were divided into 3 groups: 19 with HTN and PICA-CFR less than 2.0 (group A); 23 with HTN and PICA-CFR of 2.0 or more (group B); and 16 who were normotensive with PICA-CFR of 2.0 or more (group C). RESULTS: Baseline peak diastolic velocity for group A was higher than the other two groups (P < .005 vs groups B and C). PICA-width ratio was higher than the other two groups (P < .005 vs groups B and C). Serum propeptide of type I was 137.1 +/- 16.6 ng/mL in group A, 96.2 +/- 13.7 ng/mL in group B, and 78.8 +/- 11.2 ng/mL in group C (P < .0001 vs group B and group C). PICA-CFR was closely related to serum propeptide of type I (P < .001, r = -0.723). CONCLUSION: The impaired PICA-CFR is related to myocardial fibrosis in patients with HTN, chest pain, and normal coronary angiogram results.

Relation between peripheral vascular endothelial function and coronary flow reserve in patients with chest pain and normal coronary angiogram.

To evaluate the relation between peripheral vascular endothelial function and coronary flow reserve (CFR), we assessed flow mediated dilation (FMD) of brachial artery and the intima-media thickness (IMT) of the carotid artery in 32 subjects (mean age 58+/-9 years, M/F=9:23 ) with chest pain and normal coronary angiogram. The subjects were divided into 2 groups according to CFR >or=2.1 or <2.1 measured with transthoracic echocardiography in distal left anterior descending coronary artery. We found % FMD was decreased in the group with CFR <2.1 than those of CFR >or=2.1 and CFR was correlated with peripheral FMD. However, IMT was not different between two groups. These results suggest that microvascular dysfunction is primarily related to endothelial dysfunction rather than advanced atherosclerosis and because it is a generalized process that involves the whole arteries, the measurement of brachial FMD can be a useful diagnostic tool to evaluate microvascular dysfunction in patients with chest pain and normal coronary angiogram.

Left bundle branch block disturbs left anterior descending coronary artery flow: study using transthoracic Doppler echocardiography.

BACKGROUND: This study was performed to evaluate the influence of left bundle branch block (LBBB) on left anterior descending coronary artery (LAD) flow. METHODS: We divided 89 subjects (34 males and 55 females, mean age 64 +/- 14 years) into an LBBB group (n = 40), a right ventricular (RV) pacing group (n = 26), and a control group (n = 23). All of the patients were examined with surface electrocardiography (ECG) and underwent transthoracic Doppler echocardiography (TTE) to measure QRS duration on the ECG, left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), and left ventricular end-systolic volume (LVESV). Coronary flow velocity was measured in the distal LAD with TTE, and the percentage of diastolic flow duration (%DD) was expressed as the percentage of diastolic duration of coronary artery flow divided by the R-R interval. RESULTS: The %DD of the LAD was significantly shorter in the LBBB group (40.4% +/- 12.4%) with LVEF < 50% than in the RV pacing group (60.3% +/- 7.3%) and the control group (59.3% +/- 7.6%) (P < .01 vs the control and RV pacing groups), and it was also significantly shorter in the LBBB group (49.3% +/- 10.5%) with LVEF > or = 50% than in the control and RV pacing groups (P < .01 vs the control and RV pacing groups). In the LBBB group, the %DD of the LAD had a positive correlation with LVEF (P < .05; r = .50), a negative correlation with LVEDV (P < .05; r = -.57), and a negative correlation with QRS duration (P < .05; r = -.41). CONCLUSIONS: Unlike RV pacing, LBBB itself can disturb the coronary perfusion of the LAD through shortening of the diastolic flow duration. Furthermore, systolic dysfunction potentiates the shortening effect of diastolic flow duration by LBBB. Whether left ventricular systolic dysfunction is the result of the coronary flow disturbance by LBBB or vice versa merits further investigation.

Digitized QT dispersion by the Valsalva maneuver in hypertensive patients.

BACKGROUND: Hypertension is an important risk factor for sudden cardiac death, of which the incidence increases with increases in blood pressure. Prolonged QT dispersion has been identified to indicate increased risk of life-threatening ventricular arrhythmia and sudden cardiac death. In this study, QT dispersion was investigated in hypertensive patients during the strain phase of the Valsalva maneuver. METHODS: The study population included 75 subjects: 25 with normal blood pressure (Control), 25 with stage I hypertension (Group A), and 25 with stage II hypertension (Group B). Electrocardiography for QT dispersion was recorded at 25 mm/sec paper speeds before and during the Valsalva maneuver. RESULTS: The patients in Group B were significantly older than the controls (p<0.05). Differences in sex, smoking, diabetes, angina, and hyperlipidemia were not statistically significant between the three groups. The basal QT dispersion was 25.3 +/- 18.3 ms in the controls, 39.0 +/- 17.8 ms in Group A, and 36.8 +/- 18.8 ms in Group B. The QT dispersion was significantly higher in group A patients than the controls (p<0.05). In Group B only, a significant increase in QT dispersion was observed during the Valsalva maneuver, compared to conditions prior to the Valsalva maneuver (p<0.05). CONCLUSION: The conditions that increase intrathoracic pressure may increase QT dispersion and severe hypertensive patients should avoid these conditions.

Percutaneous transluminal coronary angioplasty for coronary artery stenosis in a young patient with long term Kawasaki Disease.

Kawasaki Disease (KD) is an acute, febrile, multisystem disease of children. More severe complications in 15-25% of cases include, the development of coronary aneurysms, ischemic heart disease, and sudden cardiac death. The standard treatment for significant coronary artery stenosis has generally been aortocoronary bypass surgery, although percutaneous transluminal coronary angioplasty (PTCA) has been described in a small number of patients. This report describes a 14 year old boy with a history of KD who developed multiple coronary aneurysms and stenosis. We performed PTCA, which was successful in relieving the stenosis of the left circumflex artery.