Pneumomediastinum mimicking acute ST-segment elevation myocardial infarction

Electrocardiographic spiked-helmet sign in critical non-cardiac illness

The spiked-helmet sign (SHS) is an electrocardiographic finding characterised by a distinctive pattern associated with critical illness, resolving once the clinical condition improves. While the underlying mechanism remains uncertain, different mechanisms have been proposed to account for these findings including changes in intrathoracic or intra-abdominal pressures, transient compression of the coronary arteries, repolarisation abnormalities and electromechanical artefacts. We describe the development of the SHS in a patient with underlying left bundle branch pacing following the development of respiratory failure due to haemoptysis and review proposed mechanisms for its pathophysiology.

ST-Segment Elevation Secondary to Spontaneous Pneumomediastinum in the Setting of COVID-19 Infection: A Case Report and Literature Review

A 45-year-old male presented with shortness of breath, cough,and chest discomfort. He reported positive test results for coronavirus disease 2019 (COVID-19) four days prior; this was confirmed by a second test administered at the hospital. Results of a chest CT, consistent with COVID-19 pneumonia, also revealed pneumomediastinum (PM). EKG showed ST elevations in the inferior leads with no reciprocal changes. Emergent cardiac catheterization showed that he had no stenosis in his major coronary arteries. His symptoms resolved after 25 days of hospitalization and the patient was ultimately discharged. This case highlights the importance of recognizing spontaneous PM as a complication of COVID-19 along with its uncommon presentation of ST elevation in order to prevent unnecessary invasive procedures.

Spontaneous pneumomediastinum mimicking acute pericarditis

ST elevations on electrocardiogram (ECG) have a broad differential diagnosis that can vary from benign to more ominous pathologies. These include early repolarization, coronary vasospasm, acute pericarditis, ST-elevation myocardial infarction, ventricular aneurysms, and dissecting aneurysm of the aorta reaching the pericardium. ST-segment changes may also provide a clue to the presence of spontaneous pneumomediastinum (SPM). These ECG changes are seldom reported in literature. We describe two SPM cases with concomitant pneumopericardium that closely mimicked acute pericarditis with a deceptive clinical spectrum.

Diagnostic and prognostic value of low QRS voltages in cardiomyopathies: old but gold

The interpretation of 12-lead resting electrocardiogram (ECG) in patients with a definitive diagnosis or with the suspicion of a cardiomyopathy represents a cornerstone for the diagnostic work up and management of patients. Although low electrocardiographic QRS voltages (LQRSV) detected by 12-lead resting ECG have historically been acknowledged by physicians, in view of recent evidence on the demonstration of myocardial scar by cardiac magnetic resonance and its relevance as a cause of sudden cardiac death even in young individuals, a new interest has been raised about the utility of LQRSV in the clinical practice. Beyond their diagnostic value, LQRSV have also demonstrated a prognostic role in different cardiomyopathies. The present review summarizes the diagnostic and prognostic value of LQRSV in cardiomyopathies, reporting the new evidence, primarily based on advanced imaging studies, supporting the clinical utility of this parameter.

Pneumomediastinum, ST elevation and urgent cardiac catheterisation: a crucial triad?

Pneumomediastinum (PNMD) entails the presence of air or other gas in the mediastinum and is also known as mediastinal emphysema. PNMD may cause a wide variety of signs and symptoms, as well as ECG abnormality, including ST segment changes. We present a 56-year-old man admitted to our hospital after a facial trauma. After undergoing tracheostomy, he complained of chest discomfort. A chest X-ray in the posteroanterior view showed PNMD, and an ECG was suggestive of inferior-lateral wall myocardial infarction. An urgent cardiac catheterisation identified a critical obstruction at the origin of the right coronary artery. Following a balloon angioplasty, chest discomfort continued; and the ECG ST segments did not show any dynamic change during the subsequent 72 hours. We urge clinicians to perform a comprehensive workup for every patient presenting with PNMD and ST segment changes, to prevent unnecessary invasive procedures.

PostOperative ST-segment elevation: not a blocked coronary artery, then what?

ST‐segment elevation is well known for its diagnostic value for transmural myocardial infarction due to acute thrombotic occlusion of a coronary artery, and often requires emergency reperfusion therapy. However, ST segment is by no means pathognomonic for acute coronary events. Here, we report a case of ST‐segment elevation after hepatectomy secondary to an unusual etiology.

Pneumomediastinum and Mediastinal Hematoma Secondary to Right Brachiocephalic Vein Thrombectomy Mimicking STEMI

A 50-year-old male with a history of hemodialysis dependent chronic kidney disease presented to our emergency department with acute midsternal crushing chest pain. Patient was diagnosed with acute anterolateral wall Myocardial Infraction due to the presence of corresponding ST segment elevations in EKG and underwent emergent cardiac catheterization which revealed normal patent coronaries without any disease. He continued to have chest pain for which CT of the chest was done which revealed pneumomediastinum with mediastinal hematoma, due to the recent attempted thrombectomy for thrombus in his right brachiocephalic vein.

Spiked helmet sign after percutaneous left stellate ganglion ablation in a patient with long QT syndrome

"Spiked helmet" is a type of ST elevation, which is generally observed in critically ill patients and associated with very poor prognosis. Here we present a case of previously undiagnosed long QT syndrome admitted with polymorphic ventricular tachycardia (PMVT) unresponsive to pharmacological treatment and developed "spiked helmet" sign after left percutaneous stellate ganglion ablation.

Pneumomediastinum and ST-Segment Elevation

Although acute myocardial infarction is the most clinically significant cause of ST-segment elevation, other serious clinical conditions have been reported with this electrocardiographic abnormality. We report a patient with pneumomediastinum who presented with dyspnea and electrocardiographic changes mimicking ST-segment elevation myocardial infarction. Coronary angiography demonstrated no evidence of myocardial injury and the electrocardiographic abnormality promptly resolved with the resolution of the pneumomediastinum.

Spiked helmet sign: An under-recognized electrocardiogram finding in critically ill patients

A 77-year-old male patient presented with rhabdomyolysis. He developed progressive respiratory failure and acute respiratory distress syndrome during his hospital stay requiring mechanical ventilation. An electrocardiogram during mechanical ventilation showed findings suggestive of ST elevation myocardial infarction. Closer review showed dome and spike findings that have been likened to a “spiked helmet.” This finding has been associated with significant mortality. We discuss this under-recognized finding and the potential contributing mechanisms.

Transient elevation of ST-segment due to pneumothorax and pneumopericardium

ST-segment elevation, observed in the critically ill patients, almost always raises the suspicion of ischemic heart disease. However, nonischemic myocardial and non-myocardial problems in these patients may also lead to ST-segment elevation. Pneumothorax and pneumopericardium have been rarely reported as a cause of transient ST-segment elevation. The authors report the case of a patient admitted to the emergency care unit because of a respiratory failure requiring mechanical ventilatory support. As the patient showed signs of clinical deterioration, a pneumothorax was clinically diagnosed. Chest radiography after thorax drainage also disclosed a pneumopericardium. The 12-lead electrocardiogram recorded before the thoracic drainage revealed an ST-segment elevation, which normalized after the surgical procedure. Ischemic myocardial biomarkers were negative. The authors call attention to the right-sided pneumothorax associated with pneumopericardium as an unusual cause of ST-segment elevation.

Electrocardiographic ST-segment elevation myocardial infarction in critically ill patients: an observational cohort analysis

OBJECTIVE

To investigate the specificity of the electrocardiographic diagnosis of ST-segment elevation myocardial infarction in the critical care unit setting.

DESIGN

Retrospective observational cohort analysis.

SETTING

An 880-bed tertiary care teaching hospital with 120 intensive care unit beds.

PATIENTS

The population included medical, surgical, trauma, and neurosurgical intensive care unit patients.

INTERVENTIONS

Electrocardiograms were systematically collected to include all consecutive recordings over a 15-month period in which the interpretation software indicated ***ACUTE MI***. Patient demographics, markers of intensive care unit complexity, and hospital mortality were ascertained. The electrocardiograms were then further evaluated by a blinded, board-certified cardiologist for agreement or disagreement with the interpretation software. Serum troponin measurements obtained within 96 hrs of electrocardiogram acquisition were used to determine the likelihood of myocardial infarction.

MEASUREMENTS AND MAIN RESULTS

Over the 15-month study period, the interpretation software diagnosed ST-segment elevation myocardial infarction in 67 of 2243 intensive care unit patients (2.99%) who had an electrocardiogram performed. In the final study population of 46 cases with electrocardiographic ST-segment elevation myocardial infarction, 85% had peak troponin elevation<5 ng/mL, a strong suggestion against clinical ST-segment elevation myocardial infarction. The cardiologist agreed with the computer interpretation in 39% (18 of 46) of cases, but of those 18 patients, only six showed a significant rise in the troponin level. The cardiologist disagreed with the computer interpretation in 60.9% (28 of 46) of cases and of those, one patient had a marked elevation of the cardiac troponin.

CONCLUSIONS

ST-segment elevation myocardial infarction in the intensive care unit is a relatively common electrocardiographic reading both by standard interpretation software and by expert evaluation. In contrast to nonintensive care unit patients who present with chest pain, the electrocardiographic ST-segment elevation myocardial infarction diagnosis seems to be a nonspecific finding in the intensive care unit that is frequently the result of a variety of nonischemic processes. The vast majority of such patients do not have frank ST-segment elevation myocardial infarction.

Spontaneous pneumomediastinum: a report of 2 cases

We report 2 cases of spontaneous pneumomediastinum (SPM) with clinical presentations similar to pericarditis, including positional chest pain, tachycardia, a precordial rub, and electrocardiographic changes. Chest radiography is the most commonly used imaging modality for diagnosis, but the findings may be subtle. In select patients, a more extensive diagnostic approach is warranted. Spontaneous pneumomediastinum is self-limiting, and the risk of recurrence is negligible. These cases serve to illustrate the need to include spontaneous pneumomediastinum in the differential diagnosis of pericarditis.