Darae Kim

The different infarct patterns between adulthood-onset and childhood-onset moyamoya disease

Background and purpose The pattern of infarctions based on the findings of diffusion-weighted image was assessed, and it was also investigated whether there are any age-specific differences in patients with moyamoya disease (MMD). Methods The subjects were 66 consecutive patients with MMD who had an acute cerebral infarction. Each ischaemic lesion was categorised into one of seven patterns (gyral, atypical territorial, honeycomb, classic territorial, multiple-dot, borderzone, deep lacunar) based on diffusion-weighted image findings. The patterns were compared between adulthood-onset MMD (A-MMD, ≥20 years old, 34 patients) and childhood/adolescent-onset MMD (C-MMD, <20 years old, 32 patients) according to their ages of infarct presentation. Results A total of 91 infarct patterns were observed from 66 patients. The gyral, atypical territorial, and honeycomb patterns, which are not usually seen in conventional stroke patients, were common in MMD (68.1%). Among all patterns, a gyral pattern was most common (40/91, 44.0%). Borderzone and deep lacunar patterns were infrequent. Gyral and borderzone patterns were more frequently seen in the C-MMD group, whereas a honeycomb pattern was not seen in young patients. Honeycomb pattern was more common at advanced vascular stages. Infarctions confined to the cortex were more common in the C-MMD group (26/32, 75.0%) than in A-MMD patients (14/34, 41.2%). Conclusions Moyamoya disease showed various characteristic and age-specific infarct patterns. Different infarct patterns between the A-MMD and C-MMD groups may be associated with age-specific vulnerability of the brain to ischaemia, stage of arteriopathy or changes of abnormal collateral pathways.

Comparison of two different doses of single bolus steroid injection to prevent atrial fibrillation recurrence after radiofrequency catheter ablation.

Purpose Steroids may play a role in preventing the early recurrence of atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA). However, optimal doses and route of steroid delivery have not yet been determined. This study evaluated the effect of two different doses of a single bolus injection of steroids on AF recurrence after RFCA. Materials and Methods Of 448 consecutive AF patients who underwent RFCA, a single steroid bolus was injected into 291 patients. A low-dose steroid group (n=113) received 100 mg of hydrocortisone and a moderate-dose steroid group (n=174) received 125 mg of methylprednisolone. We used propensity-score matching to select patients as follows: control (n=95), low-dose (n=95), and moderate-dose steroid groups (n=97). Results Pericarditis developed in 1 (1.1%) control patient, 2 (2.1%) low-dose patients and 0 moderate-dose patients. Maximum body temperature and C-reactive protein were significantly decreased in the moderate-dose steroid group compared to the other groups (p<0.01). The number of patients of early AF recurrence (≤3 months) did not differ among three groups. Early recurrence was 24 (25%) in the control, 24 (25%) in the low-dose and 25 (26%) in the medium-dose groups (p=0.99). Compared with control group, low-dose or moderate-dose steroid treatment did not effectively decrease mid-term (3-12 months) AF recurrence [22 (23%) vs. 23 (24%) vs. 18 (19%); p=0.12]. Conclusion A single injection of moderate-dose steroid decreased inflammation. However, single bolus injections of low-dose or moderate-dose steroids were not effective in preventing immediate, early or midterm AF recurrence after RFCA.

Incremental Value of Left Atrial Global Longitudinal Strain for Prediction of Post Stroke Atrial Fibrillation in Patients with Acute Ischemic Stroke

Background Atrial fibrillation (AF) is a well-established risk factor for stroke. Interestingly, ischemic stroke increases risk of incident AF in patients without prior diagnosed AF. For better risk stratification for post-stroke AF, we studied left atrial (LA) size and mechanical function using two-dimensional (2D) speckle tracking imaging in patients with acute ischemic stroke. Methods A total of 227 patients (132 males, age 67 ± 12) with acute ischemic stroke without a history of AF underwent 2D transthoracic echocardiography and speckle tracking imaging for the assessment of LA volume index and global LA longitudinal strain (LALS). From clinical variables, the CHA2DS2-VASc score and National Institute of Health Stroke Scale (NIHSS) were calculated in each patient. Post-stroke AF was defined as newly diagnosed AF during the course after ischemic stroke. Results Post-stroke AF occurred in 25 patients (11%). Patients with post-stroke AF were older and showed a higher tendency of CHA2DS2-VASc score, significantly higher log NIHSS, larger LA volume index and lower global LALS than those without. In multivariate analysis, global LALS was an independent predictor for post-stroke AF (hazard ratio 0.90, 95% confidence interval 0.83.0.97, p < 0.01) after controlling for confounding factors. Furthermore, global LALS provided incremental predictive value for post-stroke AF over the CHA2DS2-VASc score, NIHSS, and LA volume index. The global LALS < 14.5% better distinguished post-stroke AF (area under the curve 0.837, sensitivity 60%, specificity 95%, p < 0.01) than CHA2DS2-VASc score. Conclusion Global LALS as a marker of LA mechanical function has incremental predictive value for post-stroke AF in patients with acute ischemic stroke.

Clinical Implications and Determinants of Left Atrial Mechanical Dysfunction in Patients With Stroke.

Background and Purpose— The evaluation of sources of cardioembolism with transesophageal echocardiography (TEE) in patients with stroke is crucial but semi-invasive. We hypothesized that the size and mechanical function of the left atrium (LA) assessed by transthoracic echocardiography (TTE) could provide useful information on high risk of cardioembolism on TEE in patients with stroke. Furthermore, we sought to define the determinants of LA mechanical dysfunction in these patients. Methods— A total of 248 patients with acute ischemic stroke (147 men; 64±13 years) who underwent 2-dimensional and speckle tracking TTE followed by TEE were analyzed. Results— LA appendage emptying velocity, prevalence of LA or LA appendage thrombus, prevalence of aortic plaques, and incidence of embolic stroke showed significant differences among the 4 groups classified according to the median values of the LA volume index and global LA longitudinal strain (LALS). Patients at high risk of cardioembolism evidenced by TEE revealed significantly larger LA volume index and lower global LALS than those without. Global LALS (cutoff, 11.5%; area under the curve, 0.947; sensitivity, 100%; specificity, 91%; P<0.001) revealed a significantly better diagnostic power (P=0.04) for LA or LA appendage thrombus than LA volume index (cutoff, 36.2 mL/m2; area under the curve, 0.823; sensitivity, 88%; specificity, 75%; P=0.002). Age, left ventricular systolic function, LA volume index, and pulse wave velocity were independent determinants for global LALS. Conclusions— LA mechanical dysfunction is closely associated with high risks of cardioembolism. Global LALS assessed by speckle tracking TTE well discriminates the presence of LA or LA appendage thrombus on TEE in patients with acute ischemic stroke.

Hypertensive response to exercise: mechanisms and clinical implication

A hypertensive response to exercise (HRE) is frequently observed in individuals without hypertension or other cardiovascular disease. However, mechanisms and clinical implication of HRE is not fully elucidated. Endothelial dysfunction and increased stiffness of large artery contribute to development of HRE. From neurohormonal aspects, excess stimulation of sympathetic nervous system and augmented rise of angiotensin II seems to be important mechanism in HRE. Increasing evidences indicates that a HRE is associated with functional and structural abnormalities of left ventricle, especially when accompanied by increased central blood pressure. A HRE harbors prognostic significance in future development of hypertension and increased cardiovascular events, particularly if a HRE is documented in moderate intensity of exercise. As supported by previous studies, a HRE is not a benign phenomenon, however, currently, whether to treat a HRE is controversial with uncertain treatment strategy. Considering underlying mechanisms, angiotensin receptor blockers and beta blockers can be suggested in individuals with HRE, however, evidences for efficacy and outcomes of treatment of HRE in individuals without hypertension is scarce and therefore warrants further studies.

Predictors of Long-Term Outcomes of Percutaneous Mitral Valvuloplasty in Patients with Rheumatic Mitral Stenosis.

Purpose We determined factors associated with long-term outcomes of patients who underwent successful percutaneous mitral balloon valvuloplasty (PMV). Materials and Methods Between August 1980 and May 2013, 1187 patients underwent PMV at Severance Hospital, Seoul, Korea. A total of 742 patients who underwent regular clinic visits for more than 10 years were retrospectively analyzed. The endpoints consisted of repeated PMV, mitral valve (MV) surgery, and cardiovascular-related death. Results The optimal result, defined as a post-PMV mitral valve area (MVA) >1.5 cm2 and mitral regurgitation ≤Grade II, was obtained in 631 (85%) patients. Over a mean follow up duration of 214±50 months, 54 (7.3%) patients underwent repeat PMV, 4 (0.5%) underwent trido-PMV, and 248 (33.4%) underwent MV surgery. A total of 33 patients (4.4%) had stroke, and 35 (4.7%) patients died from cardiovascular-related reasons. In a multivariate analysis, echocardiographic score [p=0.003, hazard ratio=1.56, 95% confidence interval (CI): 1.01–2.41] and post-MVA cut-off (p<0.001, relative risk=0.39, 95% CI: 0.37–0.69) were the only significant predictors of long-term clinical outcomes after adjusting for confounding variables. A post-MVA cut-off value of 1.76 cm2 showed satisfactory predictive power for poor long-term clinical outcomes. Conclusion In this long-term follow up study (up to 20 years), an echocardiographic score >8 and post-MVA ≤1.76 cm2 were independent predictors of poor long-term clinical outcomes after PMV, including MV reintervention, stroke, and cardiovascular-related death.

Different characteristics, clinical outcomes, and left atrial reverse remodeling in patients with mitral stenosis maintaining sinus rhythm for at least 10 years after successful percutaneous mitral valvuloplasty

Background: We aimed to investigate the characteristics and echocardiographic changes in patients with severe mitral stenosis (MS) who maintained sinus rhythm (SR) for at least 10 years after successful percutaneous mitral balloon valvuloplasty (PMV). Methods: We retrospectively reviewed 107 patients who had successful PMV and follow-up echocardiography for at least 10 years without mitral valve surgery. Preprocedural, immediate postprocedural (PMV), and long-term follow-up echocardiography (at least 10 years after PMV) data were reviewed. Results: The mean follow-up time after PMV was 15 ± 4 years for SR patients (n = 50) and 16 ± 4 years (p = 0.172) for atrial fibrillation (AF) patients (n = 57). The left atrial diameter was significantly decreased in SR patients in the follow-up echocardiography images compared to its pre-PMV value (46.7 ± 6.3 vs. 43.3 ± 6.2 mm, respectively), whereas it was significantly increased in patients with AF (53.9 ± 7.1 vs. 58.1 ± 8.7 mm). In multivariate analysis, preprocedural AF (odds ratio [OR] 14.50, p = 0.001) and LA diameter ≥50 mm (OR 8.81, p < 0.001) were independently associated with increased risk for the presence of AF after successful PMV. Conclusion: Very long-term maintenance of SR after successful PMV was associated with preprocedural SR and LA diameter < 50 mm.

Metallic Foreign Body in Heart Mimicking Moderator Band

A foreign body in heart is rare, but it is more frequently encountered than the past as iatrogenic causes are increasing. Clinicians should be aware that foreign body could be mistaken for normal structure of heart. In order for accurate diagnosis, multi-imaging modalities should be used for information of exact location, mobility and hemodynamic effects. A decision to intervene should be made based on potential harms harbored by foreign bodies. Endovascular retrieval should be considered as an option. However, when fatal complications occur or when foreign bodies are embedded deeply, a surgical removal should be attempted.

Prosthetic Mitral Valve Leaflet Escape

Leaflet escape of prosthetic valve is rare but potentially life threatening. It is essential to make timely diagnosis in order to avoid mortality. Transesophageal echocardiography and cinefluoroscopy is usually diagnostic and the location of the missing leaflet can be identified by computed tomography (CT). Emergent surgical correction is mandatory. We report a case of fractured escape of Edward-Duromedics mitral valve 27 years after the surgery. The patient presented with symptoms of acute decompensated heart failure and cardiogenic shock. She was instantly intubated and mechanically ventilated. After prompt evaluation including transthoracic echocardiography and CT, the escape of the leaflet was confirmed. The patient underwent emergent surgery for replacement of the damaged prosthetic valves immediately. Eleven days after the surgery, the dislodged leaflet in iliac artery was removed safely and the patient recovered well.

Impact of Ambulatory Blood Pressure on Early Cardiac and Renal Dysfunction in Hypertensive Patients without Clinically Apparent Target Organ Damage

Purpose Impaired left ventricular (LV) global longitudinal strain (GLS) and the presence of microalbuminuria indicate early cardiac and renal dysfunction. We aimed to determine the relationships among 24-h ambulatory blood pressure (BP) variables, LV GLS, and urine albumin creatinine ratio (UACR) in hypertensive patients. Materials and Methods A total of 130 hypertensive patients (mean age 53 years; 59 men) underwent 24-h ambulatory BP monitoring, measurements of peripheral and central BPs, and transthoracic echocardiography. Patients with apparent LV systolic dysfunction (LV ejection fraction <50%) or chronic kidney disease were not included. LV GLS was calculated using two-dimensional speckle tracking, and UACR was analyzed from spot urine samples. Results In simple correlation analysis, LV GLS showed the most significant correlation with mean daytime diastolic BP (DBP) (r=0.427, p<0.001) among the various BP variables analyzed. UACR revealed a significant correlation only with night-time mean systolic BP (SBP) (r=0.253, p=0.019). In multiple regression analysis, daytime mean DBP and night-time mean SBP were independent determinants for LV GLS (β=0.35, p=0.028) and log UACR (β=0.49, p=0.007), respectively, after controlling for confounding factors. Daytime mean DBP showed better diagnostic performance for impaired LV GLS than did peripheral or central DBPs, which were not diagnostic. Night-time mean SBP showed satisfactory diagnostic performance for microalbuminuria. Conclusion There are different associations for daytime and night-time BP with early cardiac and renal dysfunction. Ambulatory BP monitoring provides more relevant BP parameters than do peripheral or central BPs regarding early cardiac and renal dysfunction in hypertensive patients.