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Biomedical subjects

Jae K Oh

Publications and source records attributed to Jae K Oh.

At least 37 records · Page 2Linked to original sources
PubMed2006

Effects of pulmonary thromboendarterectomy on right-sided echocardiographic parameters in patients with chronic thromboembolic pulmonary hypertension.

OBJECTIVE: To determine the echocardiographic changes in the heart at 3 months and 1 year after pulmonary thromboendarterectomy (PTE) in patients with chronic thromboembolic pulmonary hypertension (CTEPH). PATIENTS AND METHODS: Thirty-two adult patients who underwent PTE for CTEPH at the Mayo Clinic in Rochester, Minn, from 1997 to 2003 were included in the study. All underwent transthoracic echocardiography before surgery. Follow-up echocardiography was performed within 3 months of surgery in 28 patients and 1 year postoperatively in 17 patients. The results were compared with baseline data. RESULTS: Within 3 months after PTE, the right ventricular end-diastolic area decreased from 38.4 +/- 12.8 cm2 to 32.5 +/- 10.4 cm2 (mean difference, 5.8 +/- 10.4 cm2; P = .02). The right ventricular end-systolic area decreased from 30.4 +/- 12.1 cm2 to 24.1 +/- 8.6 cm2 (mean difference, 6.3 +/- 10.1 cm2; P = .008). The right ventricular systolic pressure decreased significantly from 92.6 +/- 22.0 mm Hg to 55.0 +/- 19.8 mm Hg (mean difference, 40.0 +/- 24.8 mm Hg; P < .001). Tricuspid regurgitation (TR) improved from a mean grade of 2.5 +/- 1.2 to 1.2 +/- 1.1 (mean difference, 1.5 +/- 1.0; P < .001). At 12 months, the right ventricular end-diastolic area, right ventricular end-systolic area, right ventricular systolic pressure, and TR also were significantly lower than baseline values. CONCLUSION: In patients with CTEPH who undergo PTE, echocardiographic measurements of right ventricular size, systolic pressure, and TR show significant improvement immediately after surgery, which is sustained for up to 1 year after surgery.

Adult↗
PubMed2005

Evaluation of right ventricular volume and function by 2D and 3D echocardiography compared to MRI.

AIMS: Radionuclide techniques, and recently MRI, have been used for clinical evaluation of right ventricular (RV) volumes function (RVEF) and volumes; but with the introduction of 3D echocardiography, new echocardiographic possibilities for RV evaluation independent of geometrical assumptions have emerged. This study compared classic and new echocardiographic and radionuclide estimates, including gated blood pool single-photon emission computed tomography (SPECT) of RV size and function to RV volumes, and ejection fraction (RVEF) measured by magnetic resonance imaging (MRI). METHODS AND RESULTS: Thirty-four subjects with (a) prior inferior ST-elevation myocardial infarction (n=17), (b) a history of pulmonary embolism and persistent dyspnea (n=7) or (c) normal subjects (n=10) had 2D and 3D echocardiography, SPECT and MRI within 24h. End-diastolic volume and peak tricuspid regurgitation velocity were increased in patients with a history of pulmonary embolism compared to healthy subjects, 130+/-26 ml vs. 94+/-26 ml, P<0.05, and 3.3+/-1.1m/s vs. 2.3+/-0.3m/s, P<0.05, respectively, whereas no differences in RVEF were seen in the three groups. Echocardiographic as well as SPECT estimates of RV volume showed significant correlation to RV volumes by MRI. Tricuspid annular plane systolic excursion (TAPSE) had the better correlation to RVEF by MRI, r=0.48, P<0.01; whereas 3D echocardiography had a correlation of 0.42, P<0.05. Compared to MRI, 3D echocardiography underestimated RVEF by 5.9%, 95% limits of agreement 1.6-10.2%. CONCLUSION: 3D echocardiographic estimates of RV size and RVEF show only moderate correlation to MRI measures of these parameters, and simple 2D echocardiographic estimates of RV size and function show similar correlations. For routine clinical purposes the simple TAPSE may be preferred over 3D and SPECT techniques for RVEF estimation.

Aged↗
PubMed2005

Implications of periaortic hematoma in patients with acute aortic dissection (from the International Registry of Acute Aortic Dissection).

The clinical profiles, presentation, and outcomes of patients with acute aortic dissections and associated periaortic hematomas on aortic imaging have not been described in a large cohort. This study sought to assess the prognostic implications of periaortic hematomas in patients with aortic dissections and to identify factors associated with in-hospital mortality in patients with periaortic hematomas. The study population was 971 patients with acute aortic dissections enrolled in the International Registry of Acute Aortic Dissection with available imaging data on presentation with the presence or absence of periaortic hematomas. Patients with periaortic hematomas (n = 227, 23.4%) were more likely to be women, to have a history of hypertension and atherosclerosis, and to present early to the hospital. At presentation, they had greater frequencies of shock, cardiac tamponade, coma, and/or altered consciousness. Clinical outcomes were significantly worse in patients with periaortic hematomas, including significantly greater mortality (33% vs 20.3%, p <0.001). A multivariate model demonstrated periaortic hematomas to be an independent predictor of mortality in patients with aortic dissections (odds ratio 1.71, 95% confidence interval 1.15 to 2.54, p = 0.007). In conclusion, this study provides insight into the profiles, presentation, and outcomes of patients with periaortic hematomas and acute aortic dissections. The early identification and aggressive management of patients with periaortic hematomas may potentially improve clinical outcomes.

Acute Disease↗
PubMed2005

Prognostic importance of secondary pulmonary hypertension after acute myocardial infarction.

We studied 536 patients with acute myocardial infarction and echocardiographic assessment of left ventricular systolic and diastolic function and measurement of right ventricular systolic pressure. On multivariable analysis, the grade of diastolic function, mitral regurgitation severity, age, and wall motion score index were independent predictors of right ventricular systolic pressure, and an increase in right ventricular systolic pressure was independently predictive of mortality (hazard ratio 1.22 per 10 mm Hg, p <0.0001), after adjustment for conventional risk factors and left ventricular function.

Age Distribution↗
PubMed2005

Usefulness of real-time intravenous myocardial contrast echocardiography in predicting left ventricular dilation after successfully reperfused acute myocardial infarction.

The ability of real-time intravenous myocardial contrast echocardiography to predict left ventricular remodeling after reperfused acute myocardial infarction was assessed in 47 patients. Intravenous myocardial contrast echocardiography was an independent predictor of left ventricular dilation after acute myocardial infarction. In particular, normal contrast opacification within dyssynergic segments indicated a very low risk of remodeling.

Acute Disease↗
PubMed2005

Acute intramural hematoma of the aorta: a mystery in evolution.

BACKGROUND: The definition, prevalence, outcomes, and appropriate treatment strategies for acute intramural hematoma (IMH) continue to be debated. METHODS AND RESULTS: We studied 1010 patients with acute aortic syndromes who were enrolled in the International Registry of Aortic Dissection (IRAD) to delineate the prevalence, presentation, management, and outcomes of acute IMH by comparing these patients with those with classic aortic dissection (AD). Fifty-eight (5.7%) patients had IMH, and this cohort tended to be older (68.7 versus 61.7 years; P<0.001) and more likely to have distal aortic involvement (60.3% versus 35.3%; P<0.001) compared with 952 patients with AD. Patients with IMH described more severe initial pain than did those with AD but were less likely to have ischemic leg pain, pulse deficits, or aortic valve insufficiency; moreover, they required a longer time to diagnosis and more diagnostic tests. Overall mortality of IMH was similar to that of classic AD (20.7% versus 23.9%; P=0.57), as was mortality in patients with IMH of the descending aorta (8.3% versus 13.1%; P=0.60) and the ascending aorta (39.1% versus 29.9%; P=0.34) compared with AD. IMH limited to the aortic arch was seen in 7 patients, with no deaths, despite medical therapy in only 6 of the 7 individuals. Among the 51 patients whose initial diagnostic study showed IMH only, 8 (16%) progressed to AD on a serial imaging study. CONCLUSIONS: The IRAD data demonstrate a 5.7% prevalence of IMH in patients with acute aortic syndromes. Like classic AD, IMH is a highly lethal condition when it involves the ascending aorta and surgical therapy should be considered, but this condition is less critical when limited to the arch or descending aorta. Fully 16% of patients have evidence of evolution to dissection on serial imaging.

Acute Disease↗
PubMed2005

Prognostic significance of echocardiographically defined mitral regurgitation early after acute myocardial infarction.

BACKGROUND: There are limited data regarding the clinical correlates and prognostic significance of echocardiographically defined mitral regurgitation (MR) early after acute myocardial infarction (MI). The current study addressed these issues. METHODS: Seven hundred thirty-seven patients with acute MI who underwent transthoracic echocardiography with assessment of MR during their index admission were identified. Patients were followed up a median of 19 months later. The study end point was all-cause mortality. RESULTS: The prevalence of MR increased with age. It was more common in women, in patients with non-ST-elevation MI, and in those with a history of diabetes, hypertension, prior MI, or previous revascularization. Patients with MR had worse left ventricular (LV) systolic function, more LV dilatation, and more clinical evidence of LV failure. Patients with moderate or severe MR had worse survival than those with no or mild MR (hazard ratio 2.3, 95% CI 1.6-3.2, P < .0001). Even mild MR predicted a higher mortality when compared with no MR (hazard ratio 1.7, 95% CI 1.2-2.4, P = .004). Mild or moderate MR was not independently predictive of outcome, although, in multivariable analyses, a trend toward worse survival was maintained in patients with severe MR. CONCLUSIONS: Mitral regurgitation, identified by echocardiography, early after acute MI predicts poorer survival after acute MI. However, if mild or moderate, it is not an independent prognostic indicator.

Aged↗
PubMed2005

Diastolic stress echocardiography: a novel noninvasive diagnostic test for diastolic dysfunction using supine bicycle exercise Doppler echocardiography.

Left ventricular filling pressures can be estimated reliably by combining mitral inflow early diastolic velocity (E) and annulus velocity (E'). An increased E/E' ratio reflects elevated filling pressures and may be useful in assessing an abnormal increase in filling pressures for patients with diastolic dysfunction. The purpose of this study was to evaluate the feasibility of supine bicycle exercise Doppler echocardiography for assessing left ventricular diastolic pressure during exercise. Mitral inflow and septal mitral annulus velocities were measured at rest and during supine bicycle exercise (25-W 3-minute increments) in 45 patients (19 men; mean age, 59 years) referred for evaluation of exertional dyspnea. None had echocardiographic or electrocardiographic evidence of myocardial ischemia with exercise. Patients were classified according to E/E' ratio at rest: 26 had E/E' < or = 10 at rest (group 1) and 19 had E/E' > 10 (group 2). For group 1, 17 had no increase in E/E' during exercise (group 1A) and 9 did (group 1B). For group 2, E/E' did not increase during exercise. Despite different responses of E/E', there was no significant difference in changes of mitral inflow indices (E, A, E/A, deceleration time) between groups. Although the percentage of dyspnea as a primary reason for stopping exercise was similar for the groups, exercise duration was significantly shorter for groups 1B (7.2 +/- 2.5 minutes) and 2 (7.1 +/- 3.3 minutes) than in group 1A (10.4 +/- 3.7 minutes, P = .0129). Diastolic stress echocardiography using a supine bicycle is technically feasible for demonstrating changes in E/E' (filling pressure) with exercise. Our preliminary results suggest the hemodynamic consequences of exercise-induced increase in diastolic filling pressure can be demonstrated noninvasively with exercise Doppler echocardiography.

Adult↗
PubMed2005

The mitral L wave: a marker of pseudonormal filling and predictor of heart failure in patients with left ventricular hypertrophy.

OBJECTIVES: We sought to examine the relationship of the mitral L wave with echocardiographic indexes of diastolic function and heart failure (HF) events in patients with left ventricular (LV) hypertrophy (LVH). BACKGROUND: The L wave, representing middiastolic transmitral flow, is of unknown clinical and prognostic significance in patients with LVH. Methods Consecutive echocardiograms performed during a 6-month period were screened for patients with LVH, normal LV ejection fraction, in sinus rhythm, and no significant valvular disease. Clinical and echocardiographic characteristics were analyzed, and patients were followed up for incident HF. RESULTS: Of 177 patients, the L wave was present in 35 (20%) (group I) and absent in 142 (group II). Patients in group I had higher early (E) to late (A) transmitral flow velocity (E/A) ratio (1.2 vs 0.8), shorter mitral E wave deceleration time (201 vs 225 milliseconds), lower pulmonary venous systolic/diastolic velocity ratio (1.1 vs 1.6), shorter LV isovolumic relaxation time (83 vs 94 milliseconds), larger left atrial volume (36 vs 23 mL/m 2 ), and higher E to early mitral annular velocity (E/E') ratio (septal E/E', 12.2 vs 9.1; lateral annular E/E', 10.9 vs 7.8) compared with group II (all P < .05). The difference between pulmonary venous atrial reversal and mitral A wave durations was > or = 30 milliseconds in more patients of group I (70% vs 6%, P < .001). During a mean follow-up of 12.0 months, 11 patients were hospitalized for HF. The L wave was associated with a hazard ratio of 4.7 ( P = .011) for incident HF, and remained a significant predictor (hazard ratio 4.2, P = .026) after adjustment for cardiovascular risk factors. CONCLUSIONS: In patients with LVH, the mitral L wave appears to be a marker of pseudonormal LV filling and predictor of future HF events.

Aged↗
PubMed2005

Measurement of cardiac time intervals by Doppler tissue M-mode imaging of the anterior mitral leaflet.

OBJECTIVE: We sought to evaluate a new method of measuring cardiac time intervals from Doppler tissue imaging (DTI) of the anterior leaflet of the mitral valve. BACKGROUND: For a reliable analysis of the regional cardiac performance by DTI, a reference of time intervals of global cardiac events in the same cardiac cycle and based on the same imaging modality is required to reduce measurement error. METHODS: We conducted a comparison of the measurements of isovolumic contraction and relaxation time and left ventricular (LV) ejection time by DTI M-mode analysis of the anterior mitral leaflet and the traditional approach based on spectral Doppler recordings. The measurements were done in 20 control subjects and 40 patients with cardiac diseases known to affect cardiac time intervals: heart failure, aortic stenosis, and essential hypertension with LV hypertrophy. RESULTS: Mean difference in milliseconds (95% limits of agreement) of measurements were not different overall (-0.20 [-10.58; 10.18], -1.95 [-16.66; 12.76], 1.48 [-8.34; 11.34], and 0 [-0.06; 0.07] for isovolumic contraction time, LV ejection time, isovolumic relaxation time, and calculated index of myocardial performance, respectively). Intraobserver variability was low. Analysis of patients with different categories of cardiac diseases confirmed the expected values for time intervals and index of myocardial performance. CONCLUSIONS: Measurement of isovolumic periods and LV ejection time was feasible and reliable by DTI M-mode analysis of the anterior mitral valve leaflet. The DTI method can, therefore, be used for obtaining information of global events in the cardiac cycle from the same heart beat as used for analysis of regional cardiac performance.

Aged↗
PubMed2005

Left atrial index is a predictor of exercise capacity in patients with hypertrophic cardiomyopathy.

BACKGROUND: Left atrial (LA) enlargement is related to diastolic dysfunction and mitral regurgitation (MR), both of which are common in patients with hypertrophic cardiomyopathy (HCM). This study investigates the association between LA size and exercise capacity in patients with HCM. METHODS: All HCM patients who underwent a treadmill test with direct measurement of oxygen consumption (VO2) and a standard transthoracic echocardiography within 30 days in the years 2001-2003 were identified. Patients with significant comorbidities were excluded. Exercise capacity was defined as percentage of predicted peak VO2. Clinical and echocardiographic parameters were compared with those of a group of normal subjects. RESULTS: Compared with normal subjects, HCM patients had increased left atrial (LA) volume index (36 vs 21 mL/m2; P < .0001) and mitral E/e' ratio (14 vs 9; P < .0001); 27% of the patients had at least moderate MR. LA volume index demonstrated borderline correlation with exercise capacity (r = -.20; P = .06) but was an independent predictor of exercise capacity in a multivariate linear analysis, together with body mass index, heart rate at rest, and left ventricular end-systolic diameter. Including the parameters E/e' ratio or moderate or severe MR did not add incremental value to the model. CONCLUSION: LA volume index, reflecting the combined influences of MR and diastolic dysfunction, was independently associated with objective measures of exercise capacity in patients with isolated HCM.

Cardiomyopathy, Hypertrophic↗
PubMed2005

Colour M-mode velocity propagation: a glance at intra-ventricular pressure gradients and early diastolic ventricular performance.

The physiology of early-diastolic filling comprises ventricular performance and fluid dynamical principles. Elastic recoil and myocardial relaxation rate determine left ventricular early diastolic performance. The integrity of left ventricular synchrony and geometry is essential to maintain the effect of their timely action on early diastolic left ventricular filling. These factors not only are prime determinants of left ventricular pressure decay during isovolumic relaxation and immediately after mitral valve opening; they also instigate the generation of a sufficient intra-ventricular pressure gradient, which enhances efficient early diastolic left ventricular filling. Accurate assessment of diastolic (dys)function by non-invasive techniques has important therapeutic and prognostic implications but remains a challenge to the cardiologist. The evaluation of left ventricular relaxation by the standard Doppler echocardiographic parameters is hindered by their preload dependency. The colour M-mode velocity propagation of early diastolic inflow (Vp) correlates with intra-ventricular pressure gradients and is a largely preload independent index of ventricular diastolic performance. In this article, the physiologic background, utility and limitations of this promising new tool for the study of early diastolic filling are reviewed.

Blood Flow Velocity↗
PubMed2005

Contemporary results of surgery in acute type A aortic dissection: The International Registry of Acute Aortic Dissection experience.

BACKGROUND: Surgical mortality for acute type A aortic dissection reported in different experiences from single centers or surgeons varies from 7% to 30%. The International Registry of Acute Aortic Dissection, collecting patients from 18 referral centers worldwide, identifies a preoperative risk stratification scheme and a real average surgical mortality for acute type A aortic dissection in the current era. METHODS: A comprehensive analysis was completed of 290 clinical variables and their relationship to surgical outcomes in 526 of 1032 patients enrolled in the International Registry of Acute Aortic Dissection from 1996 through 2001. Extracted cases, categorized according to risk profile, were defined as unstable (group I) in the presence of cardiac tamponade; shock; congestive heart failure; cerebrovascular accident; stroke; coma; myocardial ischemia, infarction, or both; electrocardiograms with new Q waves or ST elevation; acute renal failure; or mesenteric ischemia-infarction at the time of the operation. Outside of an unstable condition, patients were categorized as stable (group II). RESULTS: The overall in-hospital mortality was 25.1%. Mortality in group I was 31.4% compared with 16.7% in group II ( P < .001). Independent preoperative predictors of operative mortality were history of aortic valve replacement (odds ratio = 3.12), migrating chest pain (odds ratio = 2.77), hypotension as sign of acute type A aortic dissection (odds ratio = 1.95), shock or tamponade (odds ratio = 2.69), preoperative cardiac tamponade (odds ratio = 2.22), and preoperative limb ischemia (odds ratio = 2.10). CONCLUSIONS: The International Registry of Acute Aortic Dissection experience confirms that patient selection plays an important role in determining surgical outcomes in patients with acute type A aortic dissection. Knowledge of significant risk factors for operative mortality can contribute to better management and a more defined risk assessment in patients affected by acute type A aortic dissection.

Acute Disease↗
PubMed2004

Differentiation of constrictive pericarditis from restrictive cardiomyopathy using mitral annular velocity by tissue Doppler echocardiography.

This study evaluated the diagnostic role of early diastolic mitral annular velocity (E') by tissue Doppler echocardiography for differentiating constrictive pericarditis from restrictive cardiomyopathy (primary restrictive cardiomyopathy and cardiac amyloidosis). The study group consisted of 75 patients (53 men, 22 women; mean age 62 years, range 27 to 87). Of these, 23 patients had surgically confirmed constrictive pericarditis, 38 had biopsy-proved systemic amyloidosis and typical echocardiographic features of cardiac involvement, and 14 had primary restrictive cardiomyopathy. Standard mitral inflow characteristics were measured. Tissue Doppler echocardiography was used to measure E' at the septal annulus. E' was significantly higher in patients with constrictive pericarditis than in those with primary restrictive cardiomyopathy or cardiac amyloidosis (12.3 vs 5.1 cm/second, p <0.001). An E' cut-off value > or =8 cm/second resulted in 95% sensitivity and 96% specificity for the diagnosis of constrictive pericarditis. There was no overlap of E' between patients who had constrictive pericarditis and those who had cardiac amyloidosis. In a subgroup analysis of restrictive cardiomyopathy, E' of patients who had cardiac amyloidosis was significantly lower than that of patients who had primary restrictive cardiomyopathy (4.6 vs 6.3 cm/second, p <0.001). Thus, E' velocity can distinguish between constrictive pericarditis and restrictive cardiomyopathy with a specific cut-off value in patients with clinical and echocardiographic evidence of diastolic heart failure.

Aged↗