European Journal of Cardiovascular Medicine

Febrile thrombocytopenia is a commonly encountered clinical presentation in tropical countries like India, typically arising from infections such as dengue, malaria, leptospirosis, chikungunya, and enteric fever. While attention is often directed toward hematological parameters and bleeding risks, cardiac involvement in these patients is frequently overlooked, despite growing recognition of myocarditis, ventricular dysfunction, and pericardial effusion as possible complications [1,2].

Pathophysiologically, myocardial injury in febrile illnesses may result from direct viral cytotoxicity, immune-mediated inflammation, or cytokine storms, contributing to transient or lasting cardiac dysfunction [3]. Clinical manifestations may be subtle or absent, necessitating imaging-based detection of structural or functional abnormalities [4,5].

Conventional transthoracic echocardiography is effective in diagnosing cardiac involvement, but its accessibility may be limited in urgent or resource-constrained environments. Handheld 2-D echocardiography, on the other hand, is emerging as a portable, dependable, and non-invasive bedside alternative, with evidence supporting its accuracy in detecting left ventricular dysfunction, pericardial effusion, and wall motion anomalies [6–8]. Studies suggest that incorporating bedside echocardiography into the evaluation of febrile patients with thrombocytopenia can enable early identification of myocardial compromise and timely therapeutic intervention [9,10].

In this context, the present study was undertaken to evaluate cardiac abnormalities in adult patients with febrile thrombocytopenia using handheld 2-D echocardiography in a tertiary care institute in India.

This prospective observational study was conducted over a 12-month period from January 2023 to December 2023 at a tertiary care hospital in India. A total of 100 adult patients presenting with febrile thrombocytopenia were enrolled after fulfilling inclusion and exclusion criteria.

Ethical approval for the study was obtained from the Institutional Ethics Committee before initiation. All patients provided written informed consent prior to participation. Confidentiality and anonymity of all participants were maintained throughout the study duration.

Patients aged 18 years and above, with documented fever and a platelet count below 50,000/μL at the time of admission, were included. Exclusion criteria were known cases of cardiomyopathy, inherited platelet disorders, corticosteroid usage, or platelet counts greater than 50,000/μL.

Detailed clinical evaluation was carried out for all patients, including history-taking, physical examination, and relevant laboratory investigations. Each participant underwent bedside 2-D echocardiography using a handheld ultrasound device with a 2–5 MHz transducer. Echocardiographic screening was performed within 24 hours of admission and included assessment of cardiac function, pericardial space, ventricular wall motion, chamber sizes, and valvular structure.

All scans were performed by trained physicians and verified by an attending cardiologist. Data collected from echocardiographic findings and clinical records were tabulated and analyzed.

Data analysis was performed using SPSS version 25.0 (IBM Corp., Armonk, NY). Categorical variables were expressed as frequencies and percentages; continuous variables as means with standard deviation. Comparisons between groups were conducted using chi-square tests, independent t-tests, or one-way ANOVA as appropriate. A p-value <0.05 was considered statistically significant.

Table 1 shows the gender distribution among the 100 patients included in the study. Males comprised the majority with 63 cases (63.0%), while females made up 37 cases (37.0%). This slight male predominance suggests that febrile thrombocytopenia with cardiac monitoring may be more frequently observed in men, though gender-specific susceptibility cannot be confirmed without further investigation.

Table 2 displays the types of febrile illness among the study population. Dengue Hemorrhagic Fever (DHF) was the most prevalent, affecting 65% of patients, followed by Dengue Shock Syndrome (DSS) in 24% and classical dengue fever in 11%. This reflects the current trend of increased severity in dengue infections, possibly linked to secondary infections or coexisting comorbidities.

Table 3 outlines the presence of cardiac symptoms at the time of admission. While 81 patients (81%) had no overt cardiac complaints, 19 (19%) presented with symptoms suggestive of myocardial involvement, such as chest discomfort or palpitations. This underlines the importance of routine cardiac screening even in the absence of clinical signs.

Table 4 presents the blood pressure status of patients upon admission. The majority (64%) had systolic BP within the normal range of 90–120 mmHg. Notably, 24% were hypotensive (<90 mmHg), suggesting a possibility of hemodynamic instability, especially in those with DSS. A smaller portion (12%) had readings above 120 mmHg, which may indicate stress response or subclinical cardiovascular dysfunction.

Table 5 provides details on Packed Cell Volume (PCV) values. Most patients (61%) had PCV between 31–40 g/dL, which is within the lower-normal range. About 12% had a PCV below 30 g/dL, indicating possible hemodilution or underlying anemia, while 27% had higher values (41–50 g/dL), possibly due to plasma leakage or dehydration common in dengue-associated complications.

Table 6 categorizes patients based on their platelet counts at the time of admission. A critical drop below 10000/cmm was observed in 4% of patients. Most had moderate thrombocytopenia, with 24% each falling within 10000–20000 and 20000–30000 ranges. Another 19% and 29% were in the 30000–40000 and 40000–50000 categories, respectively, highlighting the wide variability and severity of thrombocytopenia in febrile illnesses.

Table 7 focuses on valvular abnormalities found during echocardiographic evaluation. Most patients (93%) had structurally normal cardiac valves. Minor findings included Mitral Valve Prolapse (4%), Aortic Valve sclerosis (2%), and Rheumatic Heart Disease with Mitral Regurgitation (1%), indicating that although rare, incidental valvular pathologies can be detected during febrile episodes.

Table 8 assesses the occurrence of pericardial effusion. It was present in 22% of the patients and absent in the remaining 78%. The presence of effusion could be attributed to viral myocarditis or systemic inflammatory response, emphasizing the need for cardiac imaging in febrile patients, particularly those with thrombocytopenia.

Table 9 shows the prevalence of myocarditis detected through bedside echocardiography. Only 4% of the patients demonstrated findings suggestive of myocarditis, while the remaining 96% had no echocardiographic evidence. Though relatively uncommon, the condition can have serious implications if undiagnosed or untreated.

Table 10 evaluates the distribution of cardiac abnormalities according to fever type. Among patients with DSS, 14% showed evidence of cardiac involvement, which was significantly higher than the 1% observed in DHF cases. This pattern reinforces the notion that DSS carries a higher risk of cardiovascular compromise and requires vigilant monitoring.

Table 1: Gender distribution of patients in present study.

Table 2: Types of fever.

Table 3: Cardiac symptoms.

Table 4: Blood pressure at the time of admission.

Table 5: PCV at the time of admission in pyrexia with thrombocytopenia.

Table 6: Platelets count at the time of admission.

Table 7: Cardiac valves of patients with pyrexia with thrombocytopenia.

Table 8: Pericardial effusion in patients with febrile thrombocytopenia.

Table 9: Myocarditis in patients of pyrexia with thrombocytopenia.

Table 10: Prevalence of cardiac abnormalities in pyrexia with thrombocytopenia.

The present study highlights the relevance of bedside 2-D echocardiography in evaluating cardiac involvement among patients admitted with febrile thrombocytopenia. With a sample of 100 patients, a wide spectrum of findings was documented, revealing that subclinical cardiac dysfunction is common in this clinical context.

The gender distribution indicated a slight male predominance (63%), which is consistent with general patterns in infectious disease epidemiology in tropical settings. A significant proportion of patients (65%) were diagnosed with Dengue Hemorrhagic Fever, which aligns with the shifting burden toward more severe forms of dengue reported in recent Indian outbreaks [11].

Cardiac symptoms were noted in 19% of patients, yet echocardiographic abnormalities were more common, reinforcing the importance of imaging-based screening over sole reliance on symptomatology. This asymptomatic presentation of underlying cardiac changes echoes prior concerns regarding silent myocardial involvement in febrile illnesses, especially in viral infections [12].

Blood pressure readings showed that 24% of patients presented with hypotension, particularly in those diagnosed with Dengue Shock Syndrome (DSS). Hypotension in these cases is often multifactorial—resulting from plasma leakage, dehydration, or cardiac depression—and can complicate clinical management if not promptly identified [13].

Pericardial effusion, noted in 22% of cases, and myocarditis in 4%, are substantial findings, particularly considering that echocardiographic assessments were performed early, within 24 hours of admission. Such findings reinforce the theory that myocardial inflammation or pericardial irritation may begin early in the disease course and might remain clinically unapparent unless actively screened [14].

Among patients with DSS, 14% showed cardiac abnormalities, far exceeding the 1% observed in DHF. This reinforces the pathophysiological understanding that the severity of systemic inflammation and endothelial dysfunction in DSS directly correlates with myocardial involvement. Moreover, bedside handheld echocardiography proved to be an invaluable tool for early detection of such changes, especially in resource-limited settings [15].

Overall, this study establishes the utility of early bedside cardiac evaluation in patients with febrile thrombocytopenia. It demonstrates not only the presence of clinically relevant cardiac findings but also supports the use of portable echocardiography as a practical, effective, and scalable diagnostic aid in the Indian healthcare context.

This study emphasizes the importance of early cardiac evaluation in patients with febrile thrombocytopenia. Bedside 2-D echocardiography proved effective in detecting subclinical cardiac abnormalities, including pericardial effusion and myocarditis, particularly among patients with Dengue Shock Syndrome. These findings support the integration of portable echocardiography into routine assessment protocols in febrile illnesses, enabling timely diagnosis and improved patient care in resource-limited settings.

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