Case Report: Point of Care Ultrasound for Bedside Diagnosis of Hypertrophic Cardiomyopathy in the Post-anesthesia Care Unit

Abstract

Background

Hypertrophic obstructive cardiomyopathy (HOCM) is a relatively common inherited worldwide disease, but only a minority of cases are clinically identified. The severity of symptoms does not correlate with the severity of the disease or the risk of sudden death. HOCM is treatable, and making an accurate diagnosis is paramount to longevity. This case report highlights point of care ultrasound (POCUS) in the perioperative period to diagnose HOCM in an asymptomatic patient in the post-anesthesia care unit.

Methods

The patient experienced three syncopal episodes in the post-anesthesia care unit (PACU) following his intermediate-risk surgery. He had undergone three major surgeries previously without issues. In the post-anesthesia care unit (PACU), a POCUS was performed to aid in the differential diagnosis of the syncopal events.

Results

POCUS provided a rapid assessment of hemodynamic distress, leading to a diagnosis of HOCM in this patient, prompting timely therapy that ultimately saved his life and enabled appropriate medical management and future cardiovascular follow-up.

Conclusion

POCUS in patients with hemodynamic instability enhances clinical perioperative decision-making, aids in a rapid diagnosis, and is instrumental in instituting lifesaving measures.

Introduction

Hypertrophic cardiomyopathy (HOCM) is a common and serious condition that affects approximately 1 in 200 to 1 in 500 individuals globally. It presents a significant risk, as sudden cardiac death is a potential complication and is a leading cause of mortality among athletes and young people. Despite its prevalence, only a small percentage (10–20%) of those with the condition receive a formal diagnosis. Fortunately, advancements in diagnosis and treatment over the past few decades have substantially improved outcomes, reducing both morbidity and mortality associated with HOCM. Accurate stratification of HOCM + and timely initiation of treatment are crucial for ensuring that patients can lead long and fulfilling lives.[1] However, diagnosing HOCM can be challenging, especially in asymptomatic patients. Current clinical guidelines highlight the importance of dialogue between patients and healthcare professionals about available testing and treatment options, including risks, benefits, and individual preferences to effectively develop a personalized treatment plan.[2] Point-of-care ultrasound (POCUS) is an invaluable, real-time diagnostic tool that can be employed at the bedside for patients in hemodynamic distress. It plays a critical role in differential diagnosis, which is vital for initiating lifesaving interventions. Emphasizing the use of POCUS can significantly enhance patient care and safety for those at risk. Based on the patient’s hemodynamic status, POCUS is performed repeatedly for ongoing assessment, guidance, and necessary adjustments in therapy.[3] Current clinical evidence emphasizes the value of POCUS in the perioperative setting, and its significance in aiding diagnosis and management is expected to increase as it becomes more integrated into daily practice.

Case Presentation

The patient is a 52-year-old male diagnosed with adenocarcinoma of the colon, who has undergone a low anterior resection accompanied by a loop ileostomy.

His past medical history is significant for hypertension and chronic kidney disease. Notably, the patient never underwent cardiac testing.

His family history is significant for sudden cardiac death, his father passing away in his early fifties and his brother in his early forties.

The patient’s surgical history includes bilateral knee surgery and the aforementioned low anterior resection for colon cancer.

Physical exam reveals normal heart and bilateral breath sounds, no cardiac murmurs and no bruits. BP 157/92 mmHg, HR 73 bpm, O2 saturation 99% on room air, temperature 36.3 °C, and BMI 30.8.

Medications include lisinopril 10 mg and hydrochlorothiazide 12.5 mg once daily.

The patient reports no active cardiovascular symptoms, excellent exercise tolerance, playing soccer twice a week, and running five miles three times a week.

Laboratory data:

Baseline creatinine level of 1.6 (our institution’s standard range is 0.6–1.3), and an estimated glomerular filtration rate (eGFR) of 48 ml/min/1.73 m², calculated using the CKD-EPI formula (normal > 60). A 12-lead electrocardiogram (EKG) demonstrates sinus bradycardia at 48 bpm, otherwise normal EKG.

The patient presented for ileostomy reversal under general anesthesia, with the surgical procedure lasting 1.5 h. He received 800 ml of intravenous fluids (IVF), and the estimated blood loss (EBL) was 50 ml. The surgery was uneventful, and the patient was extubated in the operating room before being transferred to the post-anesthesia care unit (PACU), where he remained overnight due to a lack of available inpatient beds.

In the PACU, the patient was comfortable and reported no complaints. His vital signs showed an oxygen saturation of 98% on room air, a heart rate in the 80 s bpm, and a blood pressure of 128/75 mmHg. Around midnight, he attempted to get out of bed and experienced a syncopal episode, during which he was noted to have a BP of 78/40 mmHg, accompanied by an increase in heart rate to 140 bpm. He received a fluid bolus, with prompt hemodynamic recovery. A 12-lead EKG revealed no abnormalities, and laboratory values were within normal limits.

Approximately 3 h later, following a second attempt to rise from bed, the patient experienced another syncopal episode. After administering another fluid bolus, a repeat 12-lead EKG showed new non-specific ST changes in the anterolateral leads, while laboratory tests, including troponin levels, remained normal.

In the early morning, while resting in bed, the patient experienced a third syncopal episode. The third 12-lead EKG displayed worsening ST abnormalities and ST depressions in the anterolateral leads. Management included a fluid bolus, 325 mg of aspirin, and 80 mg of atorvastatin. Follow-up laboratory analysis revealed a normal high sensitivity troponin level, and previously noted ST changes were no longer present.

Differential Diagnosis

Dehydration:

The syncopal episodes may have resulted from intravascular volume depletion due to bowel preparation the night before surgery, as well as the administration of lisinopril and hydrochlorothiazide on the morning of the procedure. The patient received fluid boluses following each syncopal episode, with prompt hemodynamic recovery. His vital signs remained stable thereafter, and his urine output exceeded 5 ml/kg/h. During his overnight stay in the post-anesthesia care unit (PACU), the patient received 3 L of intravenous crystalloids, yielding a recorded urine output of 700 ml. His hemoglobin (Hb) level was 10.8 g/dL, a decrease from the preoperative level of 13.8 g/dL. The fact that intravenous fluid resuscitation resulted in hemodilution indicates that the patient was adequately resuscitated.

Acute myocardial ischemia/demand ischemia:

It is plausible that the patient experienced acute myocardial ischemia due to hypotension, as indicated by changes in the anterolateral leads. However, the transient nature of the EKG changes, combined with negative cardiac biomarkers and the absence of chest discomfort, makes this possibility less likely.

Cerebral vascular event:

Transient cerebral ischemia could potentially lead to syncopal episodes; however, there is no clinical evidence to support this in this case.

Working diagnosis:

Our working diagnosis for the syncopal events is vasovagal syncope attributed to autonomic dysfunction and orthostatic incompetence, particularly in patients with pre-existing cardiac abnormalities. During all three syncopal episodes, there were no new physical findings. Notably, a family history of sudden cardiac death in close relatives at an early age raises the possibility of an underlying structural cardiac abnormality in this patient.

Emphasizing the crucial role of point-of-care ultrasound (POCUS) in our patient’s case, the PACU attending physician, certified by the National Board of Echocardiography in Critical Care and Basic Transesophageal Echocardiography, on morning rounds performed a POCUS. The Philips SPARQ point-of-care ultrasound machine is located in the PACU and is not equipped with EKG leads. A small underfilled left ventricle (LV) was appreciated. The following measurements were obtained: left ventricle internal diameter in diastole (LVIDd) 3.0 cm (3.5–5.9 cm) and left internal diameter in systole (LVIDs) 2.0 cm (2.3–3.6 cm), with basal interventricular septum in systole (IVDs) 1.6 cm (1.1 cm), and increased LV wall thickness with marked involvement of the LV apex (2.16 cm) (Pic. 1, Pic. 2, Pic. 3, Video). The echocardiographic findings demonstrated HOCM physiology. These echocardiographic findings likely facilitated the development of hypotension and transient loss of consciousness, particularly in the early postoperative period in the setting of pre-existing intravascular volume depletion.

Pic. 1.

Initial POCUS shows the parasternal long axis (PLAX) view of a small underfilled LV with marked increased LV wall thickness of the basal septum and almost complete obliteration of the LV cavity

Pic. 2.

M-Mode of the LV through the basal septum under the MV represents mild systolic anterior motion of the mitral valve (SAM)

Pic. 3.

Parasternal short axis of the LV represents predominantly an apical form of HOCM with almost complete obliteration of the LV during systole

Video. Initial POCUS of HOCM represents a hyperdynamic LV with a small underfilled LV, marked increased LV wall thickness, and almost complete obliteration of the LV cavity.

Echocardiographic measurements post-IVF resuscitation showed LVIDd 4.5 cm and LVIDs 2.5 cm (Pic. 4).

Pic. 4.

POCUS after initiation of IV fluid resuscitation therapy represents an increase in the LV cavity and aligns with a return to baseline hemodynamic parameters

A cardiology consultation, accompanied by formal echocardiography with the Philips Affinity ultrasound system, validated the POCUS findings of hypertrophic obstructive cardiomyopathy (HOCM). POCUS measurements were consistent with official transthoracic echocardiography obtained by the cardiology consult. Subsequently, in the Intensive Care Unit (ICU), beta-blocker therapy was included in his therapy. The following day, he was discharged from the ICU and sent home. Based on his echocardiographic results (an underfilled LV), his medication regimen was further adjusted by excluding hydrochlorothiazide. He was advised to maintain proper hydration and follow up with a cardiologist for further medication adjustment and evaluation (and possible genetic testing). Eight months after discharge, the patient is doing well and is continuing with chemotherapy.

Case Discussion

Patients diagnosed with hypertrophic obstructive cardiomyopathy (HOCM) present a diverse array of symptoms, including shortness of breath, exertional chest pain, congestive heart failure, and atrial fibrillation. It is crucial to acknowledge that symptom severity does not always correlate with disease severity or the risk of sudden cardiac death. Nonetheless, a family history of sudden cardiac death necessitates further evaluation. Recent advancements in diagnostic modalities and interventional therapies have significantly reduced the annual mortality rate from 6 to 0.5%, with a reported 95% survival rate ten years post-diagnosis, ultimately enhancing both the quality of life and longevity for patients with HOCM.[4, 5]

In the case of our patient, recurrent syncopal episodes, coupled with a significant familial history of structural heart disease and sudden cardiac death, warranted comprehensive investigation. In this context, point-of-care ultrasound (POCUS) emerged as an invaluable diagnostic tool that facilitated management during the early postoperative period, as well as informed subsequent medical management and cardiovascular follow-up. Upon admission to the pre-surgical area, vital signs revealed a heart rate of 70 beats per minute, a blood pressure of 125/68 mmHg, and an oxygen saturation of 96% on room air. The patient remained asymptomatic, reported no previous history of cardiac disease, and was physically active. Notably, he had not experienced syncopal events during the postoperative phase after three significant prior surgeries. However, during his current hospitalization for an intermediate-risk surgery of shorter duration, he experienced three syncopal episodes in the early postoperative period. Initial assessments suggested intravascular volume depletion, particularly in light of bowel preparation the night before and possible autonomic dysfunction during the early postoperative phase.

The adoption of point-of-care ultrasound (POCUS) has gained traction among anesthesiologists in perioperative contexts. Emerging literature increasingly substantiates the expanded utility of POCUS with handheld ultrasound devices, which enhance timely decision-making in acute patient care settings.[6, 7] The immediate assessment of our patient, who was in hemodynamic distress, facilitated prompt diagnosis and the initiation of lifesaving interventions. The repeated application of POCUS allowed for the guiding and adjustment of treatment strategies as indicated. POCUS was instrumental in identifying a significant structural heart abnormality, which elucidated the underlying causes of the syncopal events noted in the early postoperative period. This timely intervention contributed to improved postoperative care and appropriate medication modifications prior to discharge.

In diverse perioperative contexts, POCUS has a unique advantage as an adjunct to both clinical assessment and decision-making. For patients exhibiting hemodynamic instability, POCUS is invaluable for the differential diagnosis and the initiation of immediate lifesaving therapies. Recent clinical studies provide robust evidence endorsing the use of ultrasound as a cost-effective and resource-efficient diagnostic tool, demonstrating superior sensitivity and specificity compared to other bedside assessment methods. [8] Specifically, POCUS has proven to be a more effective initial diagnostic choice than electrocardiography (EKG) for non-ST-segment elevation chest pain, underscoring its considerable value in urgent care scenarios.[9] Through the implementation of portable ultrasound examinations at the bedside, POCUS fulfills critical diagnostic and therapeutic functions across various aspects of physical examination, including cardiovascular, pulmonary, airway, neurological, and abdominal evaluations.[10] Notably, a study evaluating the integration of a perioperative POCUS program observed a significant improvement in patient care outcomes. When correlating POCUS findings with formal diagnostic examinations, there were no significant differences in detecting regional wall motion abnormalities and pericardial effusion, thereby affirming the reliability of POCUS in critical settings.[11, 12]

Conclusions

This case exemplifies the increasing significance of point-of-care ultrasound (POCUS) in perioperative settings, where it offers immediate and critical information that is essential for patient management. Despite the patient being asymptomatic, his underlying structural heart disease went undetected. He was maintained on standard post-anesthesia care unit (PACU) monitoring and supervision overnight, preventing any treatment delays that may have occurred had he been transferred to a general floor while awaiting the arrival of a rapid response team. The PACU serves as a highly monitored and controlled environment, enabling the prompt initiation of lifesaving interventions.

POCUS facilitates efficient bedside evaluations for patients experiencing hemodynamic instability, allowing for rapid assessment and diagnosis that prompts timely therapeutic measures—a combination that proved lifesaving in this instance. The application of POCUS in this case not only enabled immediate diagnostic clarity but also instigated further clinical interventions that spared the patient from the tragic fate suffered by his father and brother at an early age.

As a real-time, bedside evaluative tool, POCUS is instrumental in the evaluation of hemodynamically compromised patients, and therefore, allows quick adjustments of ongoing therapy strategies. Current clinical evidence accentuates the value of POCUS within the perioperative context, suggesting that its role in aiding diagnosis and therapeutic decision-making will continue to expand as it becomes increasingly integrated into routine clinical practice. Furthermore, as ultrasound technology advances and handheld devices become more accessible, coupled with the minimal risks associated with ultrasound, POCUS emerges as a promising diagnostic modality within the perioperative environment.

Supplementary Material

Supplementary Information The online version contains supplementary material available at https://doi.org/10.1007/s42399-025-02010-2.

Data Availability

No datasets were generated or analysed during the current study.