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1.
Singapore Med J ; 65(7): 380-388, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38973187

ABSTRACT

ABSTRACT: Ischaemia with no obstructive coronary arteries (INOCA) has been a diagnostic and therapeutic challenge for decades. Several studies have demonstrated that INOCA is associated with an increased risk of death, adverse cardiovascular events, poor quality of life and high healthcare cost. Although there is increasing recognition of this entity in the Western population, in the Asian population, INOCA remains elusive and its prevalence uncertain. Despite its prognostic significance, diagnosis of INOCA is often delayed. In this review, we identified the multiple barriers to its diagnosis and management, and proposed strategies to overcome them.


Subject(s)
Asian People , Myocardial Ischemia , Humans , Myocardial Ischemia/epidemiology , Quality of Life , Prognosis , Coronary Vessels , Prevalence , Risk Factors , Coronary Angiography , Coronary Artery Disease/diagnosis
2.
Singapore Med J ; 2024 Feb 16.
Article in English | MEDLINE | ID: mdl-38363650

ABSTRACT

INTRODUCTION: Patients with paradoxical low-flow (LF) severe aortic stenosis (AS) despite preserved left ventricular ejection fraction (LVEF) appear distinct from normal-flow (NF) patients, showing worse prognosis, more concentric hypertrophy and smaller left ventricular (LV) cavities. The left ventricular remodelling index (LVRI) has been demonstrated to reliably discriminate between physiologically adapted athlete's heart and pathological LV remodelling. METHODS: We studied patients with index echocardiographic diagnosis of severe AS (aortic valve area <1 cm2) with preserved LVEF (>50%). The LVRI was determined by the ratio of the LV mass to the end-diastolic volume, as previously reported, and was compared between patients with LF and NF AS. Patients were prospectively followed up for at least 3 years, and clinical outcomes were examined in association with LVRI. RESULTS: Of the 450 patients studied, 112 (24.9%) had LF AS. While there were no significant differences in baseline clinical profile between LF and NF patients, LVRI was significantly higher in the LF group. Patients with high LVRI (>1.56 g/mL) had increased all-cause mortality (log-rank 9.18, P = 0.002) and were more likely to be admitted for cardiac failure (log-rank 7.61, P = 0.006) or undergo aortic valve replacement (log-rank 18.4, P < 0.001). After adjusting for the effect of age, hypertension, aortic valve area and mean pressure gradient on multivariate Cox regression, high LVRI remained independently associated with poor clinical outcomes (hazard ratio 1.64, 95% confidence interval 1.19-2.25, P = 0.002). CONCLUSION: Pathological LV remodelling (increased LVRI) was more common in patients with LF AS, and increased LVRI independently predicts worse clinical outcomes.

3.
Singapore Med J ; 2023 Nov 09.
Article in English | MEDLINE | ID: mdl-38037777

ABSTRACT

Vortex formation during left ventricular diastolic filling may provide clinically useful insights into cardiac health. In recent years, there has been growing interest in the measurement of vortex formation time (VFT), especially because it is derived noninvasively. There are important applications of VFT in valvular heart disease, athletic physiology, heart failure and hypertrophic cardiomyopathy. The formation of the vortex as fluid propagates into the left ventricle from the left atrium is important for efficient fluid transport. Quantifying VFT may thus help in evaluating and understanding disease and pathophysiological processes.

4.
Singapore Med J ; 2023 Mar 24.
Article in English | MEDLINE | ID: mdl-37026360

ABSTRACT

Introduction: Management of aortic stenosis (AS) in patients with chronic kidney disease (CKD) may often be overlooked, and this could confer poorer outcomes. Methods: Consecutive patients (n = 727) with index echocardiographic diagnosis of moderate to severe AS (aortic valve area <1.5 cm2) were examined. They were divided into those with CKD (estimated glomerular filtration rate < 60 mL/min) and those without. Baseline clinical and echocardiographic parameters were compared, and a multivariate Cox regression model was constructed. Clinical outcomes were compared using Kaplan-Meier curves. Results: There were 270 (37.1%) patients with concomitant CKD. The CKD group was older (78.0 ± 10.3 vs. 72.1 ± 12.9 years, P < 0.001), with a higher prevalence of hypertension, diabetes mellitus, hyperlipidaemia and ischaemic heart disease. AS severity did not differ significantly, but left ventricular (LV) mass index (119.4 ± 43.7 vs. 112.3 ± 40.6 g/m2, P = 0.027) and Doppler mitral inflow E to annular tissue Doppler e' ratio (E: e' 21.5 ± 14.6 vs. 17.8 ± 12.2, P = 0.001) were higher in the CKD group. There was higher mortality (log-rank 51.5, P < 0.001) and more frequent admissions for cardiac failure (log-rank 25.9, P < 0.001) in the CKD group, with a lower incidence of aortic valve replacement (log-rank 7.12, P = 0.008). On multivariate analyses, after adjusting for aortic valve area, age, left ventricular ejection fraction and clinical comorbidities, CKD remained independently associated with mortality (hazard ratio 1.96, 95% confidence interval 1.50-2.57, P < 0.001). Conclusion: Concomitant CKD in patients with moderate to severe AS was associated with increased mortality, more frequent admissions for cardiac failure and a lower incidence of aortic valve replacement.

5.
Singapore Med J ; 64(9): 543-549, 2023 09.
Article in English | MEDLINE | ID: mdl-34808708

ABSTRACT

In Singapore, 9.03 million doses of the mRNA COVID-19 vaccines by Pfizer-BioNTech and Moderna have been administered, and 4.46 million people are fully vaccinated. An additional 87,000 people have been vaccinated with vaccines in World Health Organization's Emergency Use Listing. The aim of this review is to explore the reported cardiac adverse events associated with different types of COVID-19 vaccines. A total of 42 studies that reported cardiac side effects after COVID-19 vaccination were included in this study. Reported COVID-19 vaccine-associated cardiac adverse events were mainly myocarditis and pericarditis, most commonly seen in adolescent and young adult male individuals after mRNA vaccination. Reports of other events such as acute myocardial infarction, arrhythmia and stress cardiomyopathy were rare. Outcomes of post-vaccine myocarditis and pericarditis were good. Given the good vaccine efficacy and the high number of cases of infection, hospitalisation and death that could potentially be prevented, COVID-19 vaccine remains of overall benefit, based on the current available data.


Subject(s)
COVID-19 Vaccines , COVID-19 , Myocarditis , Pericarditis , Adolescent , Humans , Male , Young Adult , COVID-19/prevention & control , COVID-19 Vaccines/adverse effects , Myocarditis/etiology , RNA, Messenger , Vaccination/adverse effects
7.
Acta Cardiol ; 77(10): 884-889, 2022 Dec.
Article in English | MEDLINE | ID: mdl-34517788

ABSTRACT

BACKGROUND: Right-sided infective endocarditis (IE) related to intravenous drug use (IVDU) can follow an acute fulminant course. However, there is limited information on its longer-term clinical outcomes. AIM AND METHODS: We assessed a cohort of consecutive patients who presented with IVDU complicated by severe tricuspid valve regurgitation to determine their presentation, treatment, and long-term outcomes. In this study, severe tricuspid regurgitation (TR) was defined by the European Association of Cardiovascular Imaging criteria at initial presentation to the hospital. RESULTS: Thirty-three patients with a mean age of 35 ± 18 years (72% males) presented with IVDU associated with severe TR. At the initial presentation, 15 patients were in septic shock and required inotropes. 26 patients had septic pulmonary emboli; 10 patients had associated metastatic systemic sites of infection of which 5 patients had central nervous system (CNS) involvement. Three patients were in disseminated intravascular coagulation (DIC) and 1 patient had multi-organ failure (MOF), but not requiring dialysis or mechanical ventilation. Most patients had large tricuspid valve vegetations of >20mm. Eleven patients underwent surgery with 18% perioperative mortality. The Median follow-up was 6.4 years (0.5-11.4). Recurrent IE occurred in one-third of patients, the overall incidence of heart failure and Atrial fibrillation (AF) on follow-up was low in all 3 groups. Five-year survival was 94%. CONCLUSION: Acute severe TR following associated endocarditis IVDU results in a fulminant initial presentation, but a longer-term prognosis is good with surgical and medical treatment.


Subject(s)
Endocarditis, Bacterial , Endocarditis , Substance Abuse, Intravenous , Tricuspid Valve Insufficiency , Male , Humans , Adolescent , Young Adult , Adult , Middle Aged , Female , Tricuspid Valve/diagnostic imaging , Tricuspid Valve/surgery , Substance Abuse, Intravenous/complications , Treatment Outcome , Endocarditis, Bacterial/diagnosis , Endocarditis, Bacterial/complications , Endocarditis/complications , Endocarditis/diagnosis , Endocarditis/surgery , Tricuspid Valve Insufficiency/etiology , Tricuspid Valve Insufficiency/complications
9.
J Artif Organs ; 24(2): 217-224, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33483881

ABSTRACT

PURPOSE: The purpose of this study was to develop a simple and effective percutaneous approach to create tricuspid regurgitation in swine. METHODS: Eleven pigs (71.68 ± 7.70 kg, 3 male) were involved in this study. A grasping forceps was introduced into the right ventricle through a steerable sheath under fluoroscopic guidance and used to disrupt the tricuspid valve apparatus by avulsing leaflet or chordae tendineae repeatedly. Transthoracic echocardiography and right ventricular angiography were used to evaluate the degree of tricuspid regurgitation created. RESULTS: Ten of the 11 pigs (90.91%) achieved severe tricuspid regurgitation and 1 (9.09%) obtained moderate tricuspid regurgitation immediately after the procedure. Heart rate of the pigs significantly increased immediately after tricuspid regurgitation creation compared to baseline (88.64 ± 23.24 vs. 76.00 ± 15.30 bpm, P = 0.02), but recovered to normal level at one month follow-up (77.09 ± 11.97 bpm, P = 0.85). The right atrium, tricuspid valve annulus, and right ventricle dilated obviously one month after tricuspid regurgitation creation (dimension changes: 3.01 ± 0.35 vs. 3.56 ± 0.40 cm, P = 0.02; 2.92 ± 0.36 vs. 3.37 ± 0.39 cm, P = 0.01; 3.06 ± 0.42 vs. 3.60 ± 0.47 cm, P = 0.03 respectively). Autopsy findings showed that rupture of leaflet and/or chordae tendineae finally led to the tricuspid regurgitation. CONCLUSIONS: Severe tricuspid regurgitation can be created by a simple and effective percutaneous approach with a grasping forceps in swine model and right heart dilation can be observed consistently at one-month follow-up. This model will be valuable in pre-clinical studies for developing new tricuspid valve repair or replacement technique to treat severe tricuspid regurgitation.


Subject(s)
Cardiac Surgical Procedures/methods , Disease Models, Animal , Swine , Tricuspid Valve Insufficiency/pathology , Animals , Chordae Tendineae/diagnostic imaging , Chordae Tendineae/pathology , Chordae Tendineae/physiopathology , Echocardiography , Endovascular Procedures/methods , Heart Rate/physiology , Humans , Male , Tricuspid Valve/diagnostic imaging , Tricuspid Valve/pathology , Tricuspid Valve/physiopathology , Tricuspid Valve Insufficiency/diagnosis , Tricuspid Valve Insufficiency/physiopathology
11.
Am J Cardiol ; 128: 210-215, 2020 08 01.
Article in English | MEDLINE | ID: mdl-32534732

ABSTRACT

The clinical and imaging differences between bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV) patients with medically managed asymptomatic moderate-to-severe aortic stenosis (AS) have not been studied previously. We aim to characterize these differences and their clinical outcomes in this study. A retrospective observational study was conducted on 836 consecutive cases of isolated asymptomatic moderate-to-severe AS, with median follow-up of 3.4 years. Clinical and echocardiographic characteristics were compared between BAV and TAV patients. Subgroup analysis stratified by AS severity were performed. Survival analysis of all-cause mortality was performed using Kaplan-Meier curves and Cox proportional hazards model. Compared to BAV patients, TAV patients were older (76 ± 11 vs 55 ± 16 years, p <0.001) and had more co-morbidities including hypertension (78% vs 56%; p <0.001), diabetes (41% vs 24%; p <0.001), and chronic kidney disease (20% vs 3%; p = 0.001). TAV patients had less severe aortic valve disease than BAV patients, with a higher aortic valve area index (0.71 ± 0.20 cm2/m2 vs 0.61 ± 0.18 cm2/m2, p <0.001) and less aortic dilation (sinotubular junction: 23.7 ± 4.0 mm vs 26.9 ± 4.8 mm, p <0.001; mid-ascending aorta: 31.4 ± 4.7 mm vs 36.3 ± 6.3 mm, p <0.001). TAV patients were more likely to have eccentric left ventricular hypertrophy and less likely to have a normal geometry (p = 0.003). Competing risk analysis identified increased age (hazard ratio 1.03, 95% confidence interval 1.02 to 1.05, p <0.001) and LVEF (hazard ratio 0.98, 95% confidence interval 0.97 to 0.99, p <0.001) as independent risk factors of all-cause mortality. Valve morphology was not a significant independent risk factor for aortic valve replacement or mortality. In conclusion, asymptomatic TAV patients had more cardiovascular risk factors, less severe aortic valve disease, less sinotubular and mid-ascending aortic dilation, more severe LV remodeling.


Subject(s)
Aortic Valve Stenosis/diagnostic imaging , Aortic Valve/abnormalities , Asymptomatic Diseases , Heart Valve Diseases/diagnostic imaging , Adult , Age Factors , Aged , Aged, 80 and over , Aortic Diseases/diagnostic imaging , Aortic Diseases/epidemiology , Aortic Diseases/physiopathology , Aortic Valve/diagnostic imaging , Aortic Valve/physiopathology , Aortic Valve Stenosis/complications , Aortic Valve Stenosis/epidemiology , Aortic Valve Stenosis/physiopathology , Bicuspid Aortic Valve Disease , Case-Control Studies , Cause of Death , Dilatation, Pathologic/diagnostic imaging , Dilatation, Pathologic/epidemiology , Dilatation, Pathologic/physiopathology , Echocardiography , Female , Heart Valve Diseases/complications , Heart Valve Diseases/epidemiology , Heart Valve Diseases/physiopathology , Heart Valve Prosthesis Implantation/statistics & numerical data , Humans , Hypertrophy, Left Ventricular/diagnostic imaging , Hypertrophy, Left Ventricular/epidemiology , Hypertrophy, Left Ventricular/physiopathology , Kaplan-Meier Estimate , Male , Middle Aged , Mortality , Proportional Hazards Models , Retrospective Studies , Risk Factors , Severity of Illness Index , Stroke Volume
12.
Sci Rep ; 10(1): 7333, 2020 04 30.
Article in English | MEDLINE | ID: mdl-32355310

ABSTRACT

The global left ventricular (LV) contractility index, dσ*/dtmax measures the maximal rate of change in pressure-normalized LV wall stress. We aim to describe the trend of dσ*/dtmax in differing severity of aortic stenosis (AS) with preserved left ventricular ejection fraction (LVEF) and the association of dσ*/dtmax with clinical outcomes in moderate AS and severe AS. We retrospectively studied a total of 1738 patients with AS (550 mild AS, 738 moderate AS, 450 severe AS) and preserved LVEF ≥ 50% diagnosed from 1st January 2001 to 31st December 2015. dσ*/dtmax worsened with increasing severity of AS despite preserved LVEF (mild AS: 3.69 ± 1.28 s-1, moderate AS: 3.17 ± 1.09 s-1, severe AS: 2.58 ± 0.83 s-1, p < 0.001). Low dσ*/dtmax < 2.8 s-1 was independently associated with a higher composite outcome of aortic valve replacement, congestive cardiac failure admissions and all-cause mortality (adjusted hazard ratio 1.48, 95% CI: 1.25-1.77, p < 0.001). In conclusion, dσ*/dtmax declined with worsening AS despite preserved LVEF. Low dσ*/dtmax < 2.8 s-1 was independently associated with adverse clinical outcomes in moderate AS and severe AS with preserved LVEF.


Subject(s)
Aortic Valve Stenosis/diagnosis , Heart Ventricles/physiopathology , Aged , Aged, 80 and over , Aortic Valve/surgery , Cardiology , Female , Heart Failure/surgery , Heart Valve Prosthesis , Heart Valve Prosthesis Implantation , Humans , Male , Middle Aged , Prognosis , Retrospective Studies , Risk Assessment , Risk Factors , Severity of Illness Index , Stroke Volume , Ventricular Dysfunction, Left/physiopathology , Ventricular Function, Left
13.
J Card Surg ; 35(5): 1148-1151, 2020 May.
Article in English | MEDLINE | ID: mdl-32293046

ABSTRACT

BACKGROUND AND AIM: Cardiac sarcoma is a rare condition and may mimic atrial myxoma. We present a case report of a man with a cardiac sarcoma. METHOD: Case report presentation. RESULTS: A 68-year-old man with a permanent pacemaker presented to us with a 4-month history of breathlessness. Echocardiography revealed a large right atrial mass adherent to the pacemaker lead and a provisional diagnosis of atrial myxoma was made based on echocardiographic appearance. A 60 x 30 x 30 mm irregular lobulated tumour was surgically resected from the right atrium. Upon histopathologic examination, the tumour was consistent with an undifferentiated pleomorphic sarcoma. CONCLUSION: Cardiac sarcomas have an extremely poor prognosis and more unfortunately this man developed a surgical site infection and died of acute mediastinitis. We discuss the presentation, imaging and current surgical approaches to cardiac sarcoma. Curative treatment is currently limited for this disease.


Subject(s)
Cardiac Surgical Procedures/methods , Heart Neoplasms/surgery , Pacemaker, Artificial/adverse effects , Sarcoma/surgery , Aged , Cardiopulmonary Bypass , Diagnosis, Differential , Echocardiography , Echocardiography, Three-Dimensional , Fatal Outcome , Heart Atria/surgery , Heart Neoplasms/diagnostic imaging , Heart Neoplasms/pathology , Humans , Male , Mediastinitis , Postoperative Complications , Sarcoma/diagnostic imaging , Sarcoma/pathology , Surgical Wound Infection
14.
Singapore Med J ; 61(1): 9-14, 2020 Jan.
Article in English | MEDLINE | ID: mdl-32043160

ABSTRACT

Digoxin is a commonly prescribed drug in the management of heart failure and atrial fibrillation. Despite its widespread use, most clinicians have little experience with recognising clinical signs and symptoms that might suggest a potentially lethal drug toxicity. We herein describe two cases with specific reference to the electrocardiographic changes induced by digoxin and discuss the predisposing factors for toxicity, recognition of possible toxicity and treatment approaches.


Subject(s)
Anti-Arrhythmia Agents/adverse effects , Digoxin/adverse effects , Electrocardiography , Aged , Female , Heart Failure/drug therapy , Humans
17.
Can J Cardiol ; 35(11): 1605.e1-1605.e3, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31679630

ABSTRACT

We present a case of a 75-year-old woman with cardiac dextroposition who presented for preoperative cardiac evaluation because of exertional dyspnoea. On examination, heart sounds were best appreciated on the right, and bowel sounds were heard over the left hemithorax. Electrocardiography showed widespread T-wave inversions. No coronary artery ischemia was found. A large congenital diaphragmatic hernia with displacement of the heart to the right was found on chest radiography and confirmed on computed tomography. Surgery was subsequently uneventful. In conclusion, thorough pulmonary auscultation to detect bowel sounds in the thorax increases clinical suspicion of cardiac dextroposition.


Subject(s)
Coronary Vessels/diagnostic imaging , Dextrocardia/complications , Dyspnea/etiology , Electrocardiography , Hernias, Diaphragmatic, Congenital/complications , Aged , Dextrocardia/diagnosis , Diagnosis, Differential , Dyspnea/diagnosis , Female , Hernias, Diaphragmatic, Congenital/diagnosis , Hernias, Diaphragmatic, Congenital/surgery , Herniorrhaphy/methods , Humans , Tomography, X-Ray Computed
18.
Sci Rep ; 9(1): 11504, 2019 08 08.
Article in English | MEDLINE | ID: mdl-31395907

ABSTRACT

There has been a resurgence of interest in the treatment of severe functional tricuspid regurgitation (FTR) due to the awareness of its poor outcomes and potential percutaneous therapies. Kay bicuspidization has been adapted in percutaneous therapies but its clinical outcome remains uncertain. The present study evaluates the efficacy of Kay repair in a novel ex vivo pulsatile system. Porcine tricuspid valve (TV) (n = 3) was extracted and incorporated into a patient-specific silicon right ventricle (RV) emulating severe FTR, on which Kay repair was subsequently performed. TV area metrics and RV hemodynamic assessment by means of stereo-scopic particle image velocimetry were quantified in both FTR and post-repair conditions. Bicuspidization led to significant increase in cardiac output although the overall increment due to this approach alone was generally small, possibly due to existence of residual TR and the large reduction in TV opening area. Kinetic energy and viscous loss levels were increased post-repair, especially during diastolic filling. Main vortex structures generally maintained post-procedural. However, there was enhanced swirling motion in larger RV domain. Although this might reduce mural-thrombus risk, the relatively more complex vortex phenomenon likely resulted in elevated viscous loss observed and may potentially impact long-term adaptation. The RV hemodynamic alteration after tricuspid repair could be used to predict the success of these future transcatheter solutions.


Subject(s)
Tricuspid Valve Insufficiency/surgery , Tricuspid Valve/surgery , Animals , Female , Humans , Male , Swine
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