Byung Joo Sun

Incidence and Clinical Course of Left Ventricular Systolic Dysfunction in Patients with Carbon Monoxide Poisoning

Background and Objectives Carbon monoxide (CO) poisoning can cause tissue hypoxia and left ventricular systolic dysfunction (LVSD) requiring intensive medical management. Our objectives were to find incidence and clinical course of LVSD CO intoxicated patients and make a clinical scoring to predict LVSD. Subjects and Methods We included all consecutive patients with CO exposure in the emergency room. LVSD was defined by LVEF <50% assessed by echocardiography. We compared their clinical, chemical, radiological and electrocardiographic patterns according to the presence of LVSD. Results From May 2009 to June 2015, we included a total of 81 patients (48 men, 47±19 years old) with CO exposure in this cohort. LVSD was found in about 25 patients (31%). Nine had regional wall motion abnormality. Follow up echocardiographic examinations were available in 21 patients. Of them, 18 patients showed complete recovery in about 3 days (mean 2.8±1.7 days). Of 3 patients without recovery, 2 had significant coronary artery stenosis. LVSD was significantly associated with initial heart rate (>100/min), pulmonary edema on chest X-ray, serum NT pro-BNP (>100 pg/mL), troponin-I (>0.1 ng/mL) and lactic acid (>4.0 mg/dL) after a univariate analysis. Combining these into a clinical score, according to their beta score after a multivariate analysis (rage=0-16), allowed prediction of LVSD with a sensitivity of 84% and specificity of 91% (reference ≥8, area under the curve=0.952, p<0.001) Conclusion About 31% showed LVSD in patients with CO poisoning, and most of them (86%, 18 of 21 patients) recovered within 3 days. Patients with a higher clinical score (≥8) might have LVSD.

Impact of Valvuloarterial Impedance on Concentric Remodeling in Aortic Stenosis and Its Regression after Valve Replacement

Background Left ventricle (LV) in patients with aortic stenosis (AS) faces a double hemodynamic load incorporating both valvular stenosis and reduced systemic arterial compliance (SAC). This study aimed to evaluate the impact of global LV afterload on LV hypertrophy (LVH) before and after aortic valve replacement (AVR). Methods The study cohort included 453 patients (247 males; mean age, 64 ± 11 years) who underwent AVR. Pre- and post-AVR echocardiographic examinations were retrospectively analyzed including an index of valvuloarterial impedance (ZVA) and LV mass index/LV end-diastolic volume index (LVMI/LVEDVI) as a parameter of LVH. Results Pre-AVR LVMI/LVEDVI was 2.7 ± 0.9 g/mL with an aortic valve area (AVA) of 0.6 ± 0.2 cm2. ZVA was 5.9 ± 1.9 mm Hg/mL/m2 and showed a stronger correlation (β = 0.601, p < 0.001) with pre-AVR LVMI/LVEDVI than indexed AVA (β = 0.061, p = 0.19), transvalvular peak velocity (β = 0.211, p < 0.001). During a median follow-up of 3.5 years, patients had a 18.8 ± 10.4% decrease in the LV geometry index with a decrease in SAC from 1.20 ± 0.48 to 1.00 ± 0.38 mL/m2/mm Hg (p < 0.001). Pre-AVR LV ejection fraction (r = 0.284, p < 0.001) and ZVA (r = 0.523, p < 0.001) were independent factors associated with LVH regression in 322 patients with follow-up duration >1 year after AVR. Conclusion ZVA is a major determinant of concentric remodeling in AS before AVR and LVH regression after AVR, which should be incorporated in routine evaluation of AS.

Clinical Characteristics of Korean Patients with Bicuspid Aortic Valve Who Underwent Aortic Valve Surgery

Background and Objectives Clinical data for Korean patients with bicuspid aortic valve (BAV) that underwent aortic valve (AV) surgery are currently limited. Methods Data for 1,160 consecutive adult BAV patients who underwent AV surgery from 2000 to 2014 in 4 tertiary referral centers were retrospectively analyzed. A standard case report form was used for clinical and echocardiographic parameters. Results Mean age at the time of AV surgery was 59±13 years. The most common cause of AV surgery was aortic stenosis (AS, 892 [77%]), followed by aortic regurgitation (AR, 199 [17%]), and infective endocarditis (69 [6%]). AS showed a skewed peak in the aged population and was the predominant cause of AV surgery (87%) in patients ≥50 years of age, whereas AR (46%) and active infective endocarditis (19%) were more common in younger patients (p<0.001). Echocardiographic determination of the BAV phenotype revealed that fusion of the right coronary cusp (RCC) and left coronary cusp (LCC) was most common (622 [53%]), followed by fusion of RCC and non-coronary cusp (NCC) (313 [27%]), and fusion of LCC and NCC (42 [4%]); the BAV phenotype could not be determined in the remaining 183 patients (16%). Fusion of RCC and LCC was more commonly observed in patients with AR than in those with AS (74% vs. 49%; p<0.001). Conclusion BAV patients were characterized by distinct surgical indications according to their age. Possible associations between BAV phenotypes and surgical indications with potential impacts of ethnicity need to be tested in further studies.

Impact of Significant Mitral Regurgitation on Assessing the Severity of Aortic Stenosis

Background: Significant mitral regurgitation (MR) may reduce a pressure gradient of aortic stenosis (AS) by decreasing forward stroke volume. The study objective was to evaluate whether significant MR can cause inconsistency when assessing the severity of AS. Methods: Among 5,355 patients diagnosed with AS from 2000 to 2015, 68 were retrospectively found to have concomitant significant (moderate or greater) MR and normal left ventricular ejection fractions in normal sinus rhythm (AS with MR). As a control group, 136 patients with trivial or no MR were selected who were matched by age, gender, and left ventricular end‐systolic volume (AS without MR). Nonlinear regression was performed for data pairs (aortic valve area [AVA] vs mean pressure gradient [MPG]) using the formula AVA = a + b/√MPG. Composite clinical events were defined as aortic valve surgery warranted by the development of symptoms or left ventricular dysfunction, admission because of heart failure, and death. Results: The forward stroke volume index was significantly lower in the AS with MR group than in the AS without MR group (43.8 ± 8.3 vs 49.2 ± 10.2 mL/m2, P < .004). A significant group difference was found with respect to the relationship between (indexed) AVA and MPG (AVA, 0.02 + 4.43/√MPG vs −0.06 + 5.60/√MPG [P for interaction = .04]; indexed AVA, 0.03 + 2.66/√MPG vs −0.03 + 3.47/√MPG [P for interaction = .01]). An AVA of 1.0 cm2 corresponded to MPGs of 20.3 and 28.2 mm Hg for the groups with and without MR, respectively. Conversely, an MPG of 40 mm Hg corresponded to AVAs of 0.72 and 0.83 cm2 for the groups with and without MR, respectively. Among patients with MPGs < 40 mm Hg, clinical event rates were significantly higher in those with MR compared with those without MR (P = .009). Conclusions: This quantitative analysis demonstrated that AS severity assessed by MPG measurement may be underestimated, and thus AVA measurement is essential in patients with combined significant MR. HighlightsLower forward stroke volume is induced by significant MR.Significant MR can be a cause of inconsistency when assessing AS severity.AS severity assessed by MPG may be underestimated in patients with AS and MR.Aortic valve area measurement is essential in patients with AS and significant MR.

Long-term Survival in Korean Elderly Patients with Symptomatic Severe Aortic Stenosis Who Refuses Aortic Valve Replacement

Background and Objectives Aortic valve replacement (AVR) is the treatment of choice in severe symptomatic aortic stenosis (AS) patients. However, a substantial number of elderly patients refuse AVR and treated medically. We investigated their long-term prognosis. Methods From January 2005 to December 2016, we analyzed elderly patients with severe symptomatic AS who refused to have AVR. Results After screening of total 534 patients, we analyzed total 180 severe symptomatic AS patients (78±7 years old, 96 males). Hypertension was the most common cardiovascular risk factor (72%) and the most common symptom was dyspnea (66%). Calculated aortic stenosis area was 0.73±0.20 cm2 and mean left ventricular ejection fraction (LVEF) was 57.8±12.2%. Total 102 patients died during follow-up period (39.1±31.0 months). One-, 3-, and 5-year all-cause mortality rate was 21.1±3.0%, 43.1±3.8%, and 56.5±4.2%, respectively. Of them, 87 died from cardiac causes, and 1-, 3-, and 5-year cardiac mortality rate was 18.0±2.9%, 38.2±3.8%, and 50.7±4.3%, respectively. Their all-cause mortality and cardiac mortality were significantly higher than those of controls. Univariate analysis showed that age, anemia, LVEF, and Log N-terminal pro B-type natriuretic peptide (NT-proBNP) were significant parameters in all-cause mortality (p<0.001, p=0.001, p=0.039, and p=0.047, respectively) and in cardiac mortality (p<0.001, p<0.001, p=0.046, and p=0.026, respectively). Multivariate analysis showed that age and anemia were significant prognostic factors for cardiac and all-cause mortality. Conclusions In elderly severe symptomatic AS patients who treated medically, their 1-, 3- and 5-year all-cause mortality rate was 21.1±3.0%, 43.1±3.8%, and 56.5±4.2%, respectively. Age and anemia were significant prognostic factors for cardiac and all-cause mortality.

Impact of a Geometric Correction for Proximal Flow Constraint on the Assessment of Mitral Regurgitation Severity Using the Proximal Flow Convergence Method

Background Overestimation of the severity of mitral regurgitation (MR) by the proximal isovelocity surface area (PISA) method has been reported. We sought to test whether angle correction (AC) of the constrained flow field is helpful to eliminate overestimation in patients with eccentric MR. Methods In a total of 33 patients with MR due to prolapse or flail mitral valve, both echocardiography and cardiac magnetic resonance image (CMR) were performed to calculate regurgitant volume (RV). In addition to RV by conventional PISA (RVPISA), convergence angle (α) was measured from 2-dimensional Doppler color flow maps and RV was corrected by multiplying by α/180 (RVAC). RV measured by CMR (RVCMR) was used as a gold standard, which was calculated by the difference between total stroke volume measured by planimetry of the short axis slices and aortic stroke volume by phase-contrast image. Results The correlation between RVCMR and RV by echocardiography was modest [RVCMR vs. RVPISA (r = 0.712, p < 0.001) and RVCMR vs. RVAC (r = 0.766, p < 0.001)]. However, RVPISA showed significant overestimation (RVPISA - RVCMR = 50.6 ± 40.6 mL vs. RVAC - RVCMR = 7.7 ± 23.4 mL, p < 0.001). The overall accuracy of RVPISA for diagnosis of severe MR, defined as RV ≥ 60 mL, was 57.6% (19/33), whereas it increased to 84.8% (28/33) by using RVAC (p = 0.028). Conclusion Conventional PISA method tends to provide falsely large RV in patients with eccentric MR and a simple geometric AC of the proximal constraint flow largely eliminates overestimation.

The association between aortic regurgitation and undetermined embolic infarction with aortic complex plaque

Background Retrograde embolism from the descending thoracic aorta is one possible cause of undetermined ischemic stroke. Significant aortic regurgitation can increase the amount of reversed flow in the thoracic aorta and thus is associated with an increased incidence of stroke. Aims This study aimed to examine the association between significant aortic regurgitation and undetermined embolic infarction with aortic complex plaques. Methods This study included 380 patients with undetermined embolic stroke who did not have abnormal flow such as atrial septal defect, patent foramen ovale determined by agitated saline bubble test, intracardiac thrombi on transesophageal echocardiography, atrial fibrillation, or small vessel stroke, cerebral artery, and carotid stenosis on the brain magnetic resonance imaging. The patients were divided into the complex aortic plaques group (n = 63), which was defined as having plaque with >4 mm in thickness, ulceration, or high mobility, and the no complex aortic plaques group (n = 317). Results Transesophageal echocardiography with a bubble study, brain MRI, and laboratory tests were performed for all subjects. Significant aortic regurgitation was more prevalent in patients with undetermined embolic stroke and complex aortic plaques than in patients without complex aortic plaques (adjusted OR = 4.981; 95% CI = 1.323–18.876, P = 0.028). In addition, the distribution of complex aortic plaques according to the severity of aortic regurgitation in patients with undetermined embolic stroke had a tendency toward the ascending thoracic aorta and proximal aortic arch. Conclusions Significant aortic regurgitation may affect undetermined embolic stroke in patients with complex aortic plaques.

Normal reference values of diastolic strain rate in healthy individuals: Chronological trends and the comparison according to genders

Recently, the diastolic strain rate (DSR) utilizing speckle‐tracking echocardiography has been proposed as a novel parameter for left ventricular diastolic function. We aimed to present normal reference data for those in a large‐sized, selected group of healthy individuals.

Intrinsic changes of left ventricular function in patients with Behçet disease and comparison according to systemic disease activity

Although cardiac manifestation of Behçet disease (BD) has been described in sporadic reports, its timely diagnosis remains difficult. The objective of this study was to describe early cardiac manifestations of BD. We also performed a comprehensive classification of systemic BD activity and compared their cardiac manifestations.

Severe Leakage Presenting Mitral Regurgitation Caused by a Pseudoaneurysm Connecting the Left Ventricle and the Left Atrium Through Fistulae as a Rare Complication of Cardiac Trauma

Mitral regurgitation (MR) can develop from abnormalities in any part of the mitral valve (MV) apparatus. Although MV prolapse is the most common cause of MR especially in acute MR, abnormal connection through a fistula between the left ventricle (LV) and left atrium (LA) can also cause MR-like features. Possible causes of acquired connection between cardiac chambers include myocardial infarction infective endocarditis and iatrogenic causes such as cardiac operations. LV pseudoaneurysms are uncommon, and a pseudoaneurysm with LA to LV fistulae resulting in acute leakage with a similar clinical presentation to MR are very rare. We present a case of acute severe leakage presenting as an MR feature due to a fistula between LV and LA as a complication of a previous nonpenetrating chest injury. In this present case, LV pseudoaneurysm developed as a complication of previous blunt chest trauma. It is impossible to explain the exact mechanism of the acute onset of the patient’s symptoms. After the formation of the pseudoaneurysm, there was a high possibility that the fistula to the LA occurred after the fistula to the LV because of high pressure in the LV. The symptom of acute severe MR may have occurred after the formation of the fistula to the LA. A 66-year-old man was admitted to our cardiology clinic with complaints of dyspnea on ordinary activity and orthopnea. He underwent open thoracic surgery to control mediastinitis as a complication of an automobile accident 30 years ago. Auscultation revealed systolic murmurs and basal pulmonary crackles. Initial transthoracic echocardiography with color Doppler revealed a pseudoaneurysm (*) connecting the LA and the LV, and significant flow through the fistula from the pseudoaneurysm during systole (Fig. 1A, B). The transesophageal echocardiography revealed a 2.4x2.3 cm sized pseudoaneurysm with LV to LA fistulae (Fig. 1C, D). Contrast enhanced computed tomography (CECT) confirmed the presence of a pseudoaneurysm communicating from the LA to the LV via fistulae (Fig. 2A). After open chest and removal of the pericardium, a round pseudoaneurysm was noted near LA appendage (LAA, Fig. 3A). The connection through fistulae was confirmed with a right angle hemostatic forcep (Fig. 3B). The pseudoaneurysm was closed by a Dacron patch after the resection and then mitral valve repair was done with a ring (Fig. 3C, D). The patient was discharged without cardiac symptoms after surgery. The follow-up CECT showed complete resolution of the pseudoaneurysm (Fig. 2B).