Prevalence of left atrial appendage thrombus in patients with acute ischaemic stroke and sinus rhythm: a cross-sectional study.

OBJECTIVE: Thrombi originating in the left atrial appendage (LAA) mainly form because of atrial fibrillation (AF) and are a known cause of cardioembolic stroke. We aimed to investigate the prevalence of LAA thrombus in patients with acute ischaemic stroke (AIS) and sinus rhythm on 12-lead ECG. METHODS: From June 2019 to February 2021, we conducted a cross-sectional study wherein we performed transoesophageal echocardiography (TEE) in patients with AIS and sinus rhythm on 12-lead ECG who were referred for detection of LAA thrombus. After TEE, all patients underwent 24-hour ECG monitoring to screen for paroxysmal AF. Predictors of LAA thrombus were determined using logistic regression analysis. RESULTS: Overall, 223 patients (age: 66.2±11.3 years, men: 61.4%) were included in the study. LAA thrombus was detected in 15 patients (6.7%). Paroxysmal AF was detected in 14 of the 15 patients during 24-hour ECG monitoring. Compared with the non-thrombus group, the thrombus group had a statistically significant higher rate of spontaneous echo contrast (SEC), longer LAA, lower peak LAA emptying velocity and predominantly bilateral stroke. In the adjusted model, the presence of SEC increased the probability of LAA thrombus (OR 9.04; 95% CI 2.12 to 38.54; p=0.003). CONCLUSIONS: In patients with AIS and sinus rhythm on 12-lead ECG, our study revealed that the prevalence of LAA thrombus was 6.7% with the most prevalent aetiology being paroxysmal AF. The presence of SEC can be a predictor of LAA thrombus in these patients.

Envenoming by king cobras (Ophiophagus hannah) in Vietnam with cardiac complications and necrotizing fasciitis.

King Cobra (Ophiophagus hannah) bite is well-known for its potentially fatal neurotoxicity. However, fatalities still occur, despite specific antivenom and respiratory support. Cardiovascular disturbances, which have attracted little attention in published reports of O. hannah envenoming, could contribute to fatality. We present two cases of confirmed O. hannah envenoming in Southern Vietnam in which there were cardiac abnormalities including arrhythmias and electrocardiographic changes, as well as elevated markers of myocardial damage. Cardiac pacing was required. One patient developed critical multi-organ dysfunctions partly explained by extensive necrotizing fasciitis/myositis originating from an Aeromonas sobria wound infection. This resulted in rhabdomyolysis, disseminated intravascular coagulation and acute kidney injury. Specific antivenom reversed neurotoxic effects of envenoming. Additional therapeutic interventions included antibiotics, surgical debridement, continuous renal replacement therapy and therapeutic plasma exchange. Both patients eventually made full recoveries. Apart from the critical problem of rapidly evolving and severe neurotoxicity, our case reports also emphasises the risk of cardiotoxic envenoming, and the complications of an overwhelming secondary bacterial wound infection. We suggest a practical approach to diagnosis and management.

Risk factors for cutaneous reactions to allopurinol in Kinh Vietnamese: results from a case-control study.

OBJECTIVE: The aim of this study was to investigate risk factors for cutaneous adverse reactions (CARs) in Kinh Vietnamese. METHODS: All patients were prospectively recruited in Ho Chi Minh City. Presence of the HLA-B*58:01 allele was determined by real-time PCR-sequence-specific amplification by using the PG5801 Detection Kit (Pharmigene, Taipei). Patients with severe (SCARs) and mild (MCARs) CARs and controls were compared for differences in features prospectively collected, and odds ratios (ORs) with 95% confidence intervals (CIs) were estimated. RESULTS: On comparing 32 patients with SCARs and 395 tolerant controls, we identified eight strong risk factors: increased age (OR 15.1 [95% CI 5.8-40.1], P < 0.0001), female sex (OR 333 [40-43,453], P < 0.0001), allopurinol for asymptomatic hyperuricemia (OR 955 [120-125,847], P < 0.0001), allopurinol starting dose > 150 mg (OR 316 [101-122], P < 0.0001), diuretics intake (OR 304 [35-40,018], P < 0.0001), eGFR < 60 ml/min/1.73 m2 (OR 100 [32-353], P < 0.0001), history of allopurinol-induced skin reaction (OR 78 [6-10,808], P = 0.004), and HLA-B*58:01 carriage (OR 147 [45-746], P < 0.0001). HLA-B*58:01 allele frequency in controls was 7.3%. For MCARs (n = 74), risk factors were eGFR < 60 ml/min/1.73 m2 (OR 4.9 [1.61-14.6], P = 0.006), history of allopurinol-induced skin reaction (OR 27 [2-3777], P = 0.01), and asymptomatic hyperuricemia (OR 27 [2-3777], P = 0.01). CONCLUSION: This study confirmed 8 risk factors, including HLA-B*58:01, for SCARs and identified 3 risk factors for MCARs in Kinh Vietnamese. HLA-B*58:01 genotyping could guide the indication for allopurinol in Kinh Vietnamese patients with gout.

Age-specificity of clinical dengue during primary and secondary infections.

BACKGROUND: This study aims to estimate the age-specific risks of clinical dengue attack (i.e., the risk of symptomatic dengue among the total number of dengue virus (DENV) infections) during primary and secondary infections. METHODS: We analyzed two pieces of epidemiological information in Binh Thuan province, southern Vietnam, i.e., age-specific seroprevalence and a community-wide longitudinal study of clinical dengue attack. The latter data set stratified febrile patients with DENV infection by age as well as infection parity. A simple modeling approach was employed to estimate the age-specific risks of clinical dengue attack during primary and secondary infections. RESULTS: Using the seroprevalence data, the force of infection was estimated to be 11.7% (95% confidence intervals (CI): 10.8-12.7) per year. Median age (and the 25-75 percentiles) of dengue fever patients during primary and secondary infections were 12 (9-20) and 20 (14-31) years, respectively. The estimated age-specific risk of clinical dengue increases as a function of age for both primary and secondary infections; the estimated proportion of symptomatic patients among the total number of infected individuals was estimated to be <7% for those aged <10 years for both primary and secondary infections, but increased as patients become older, reaching to 8-11% by the age of 20 years. CONCLUSIONS/SIGNIFICANCE: For both primary and secondary infections, higher age at DENV infection was shown to result in higher risk of clinical attack. Age as an important modulator of clinical dengue explains recent increase in dengue notifications in ageing countries in Southeast Asia, and moreover, poses a paradoxical problem of an increase in adult patients resulting from a decline in the force of infection, which may be caused by various factors including time-dependent variations in epidemiological, ecological and demographic dynamics.