Isolated Right Ventricular Infarction: A Case Report and Literature Review

A Right Turn in Diagnosis: Highlighting the Importance of TAPSE in Isolated Right Ventricular Myocardial Infarction

Isolated right ventricular myocardial infarction (RVMI) is a rare but significant clinical entity that can present with atypical findings on a standard electrocardiograph (ECG). We present the case of a 65-year-old man with a history of chronic smoking and alcohol use who presented to the emergency department with acute chest pain. An initial ECG showed ST-segment elevation in lead V1 and depression in leads I, aVL, and V2-V6, which did not meet ST-segment elevation myocardial infarction (STEMI) criteria. A right-sided ECG revealed ST-segment elevation in V3R-V6R, concerning for RVMI. Notably, cardiac point of care ultrasound (POCUS) demonstrated normal left ventricular (LV) function without LV or right ventricular (RV) regional wall motion abnormalities (RWMA). However, tricuspid annular plane systolic excursion (TAPSE) was significantly reduced at 1 cm, indicating RV dysfunction despite the absence of RWMA. This is the first known case report that highlights the importance of TAPSE in assessing RV function in isolated RVMI cases. Early recognition and management are crucial, especially in patients with typical presentations, as prompt treatment can prevent complications. This case underscores the need for emergency physicians to maintain a high index of suspicion for RVMI, particularly in atypical presentations, and to utilize cardiac POCUS as an essential tool for evaluation.

Successful Bailout of Catheter-Induced Dissection in Acute Myocardial Infarction Resulting From a Nondominant Right Coronary Artery Occlusion

A 48-year-old male with a history of hyperlipidemia presented to the emergency department with chest pain. Electrocardiographic abnormalities indicated an acute coronary syndrome. Urgent coronary angiography revealed nondominant right coronary artery (RCA) occlusion. During primary percutaneous coronary intervention (PCI), a 0.014-inch floppy guidewire could not be easily advanced into the middle RCA due to poor backup support from the guiding catheter and the patient's breathing. The pressure was monitored several times after reinserting the guiding catheter. Nevertheless, the guidewire was inadvertently inserted into the false lumen from the ostium, leading to subsequent dissection during contrast injection. Intravascular ultrasound (IVUS) imaging confirmed dissection from the ostium to the middle RCA and passage of the guidewire into the false lumen. An additional guidewire was successfully inserted into the true lumen of the RCA using real-time IVUS-guided wiring. We demonstrated successful bailout stenting for catheter-induced dissection of the nondominant small RCA. Our case highlights the risk of coronary artery dissection associated with guiding catheter use, especially in a nondominant small RCA, and the importance of optimal guiding catheter selection for primary PCI. The real-time IVUS-guided wiring technique can be applied to a single 6-Fr guiding catheter and is useful for quickly inserting a guidewire into the true lumen.

Precordial ST-Segment Elevation: Anterior Myocardial Infarction or Something Else?

The differential diagnosis of ST-segment elevation on electrocardiogram is multifaceted. Particularly, in cases of precordial ST-segment elevation, considering anterior myocardial infarction is crucial. Herein, we present a case of precordial ST-segment elevation with normal left coronary arteries.

A case report: anteroseptal ST elevation due to acute isolated right ventricular infarction

BACKGROUND

Electrocardiogram (ECG) is the first diagnostic tool physicians use in diagnosing acute myocardial infarction (MI). In this case report, we present a case where the initial ECG diagnosis was that of an acute anteroseptal MI but emergency coronary angiography showed that the infarct-related artery was a small non-dominant right coronary artery (RCA) instead of the anticipated left anterior descending artery (LAD). Isolated right ventricular (RV) infarction from a non-dominant RCA is rarely seen in clinical practice, and it may exhibit ECG changes that can be confused with an acute anteroseptal MI. It is important to appreciate the subtle differences in the ECG changes that occur in either of these two types of MI for appropriate diagnosis and treatment.

CASE PRESENTATION

A 49-year-old non-smoking male with prior coronary stent implantation in LAD presented with acute chest pain and his pre-hospital ECG indicated an anteroseptal STEMI possibly due to stent thrombosis, but an emergency angiogram showed patent LAD and Circumflex arteries. There was however thrombotic occlusion of the right, non-dominant coronary artery, which was revascularized with a drug-eluting stent. The patient's chest pain and ST elevations resolved, and subsequent echo showed moderate RV systolic dysfunction in keeping with RV myocardial infarction.

DISCUSSION

RV myocardial infarction is usually due to an occlusion of the dominant RCA proximal to the origin of its RV wall branch, which often results in inferior ST elevation with reciprocal anterior ST depression. The ST elevation over V1 which would accompany RV infarction is often masked due to the more dominant electrical forces of inferior and posterior LV wall infarction. Our case demonstrates that in isolated RV infarction due to non-dominant proximal RCA occlusion, anterior ST elevation can be seen over V1-3, being most prominent in V1, which overlies the right ventricle, and resolved after restoring flow to the RCA. Spatial vector analysis of the ECG or right-sided ECG leads would be helpful to aid the diagnosis of RV infarction when clinical suspicion is present, for example when there is significant hypotension, raised jugular venous pressure but clear lung fields or deterioration after nitrate administration.