Acute coronary syndromes

Clinical Profile of Acute Coronary Syndrome Presentation to the Ladysmith Provincial Hospital: High Prevalence Among the Minority Indian Population

Background

Cardiovascular diseases were responsible for 17% of the 460236 natural deaths in South Africa in 2015. Previous studies have reported a disproportionately higher incidence of ischemic heart disease (IHD) and its risk factors among individuals of Indian descent residing in South Africa. The aim of this study was to explore the clinical profile of patients presenting with a diagnosis of acute coronary syndrome (ACS) and to compare the characteristics of patients of Indian descent to those of non-Indian descent.

Methods

Retrospective data were derived from the medical charts of 160 consecutive patients presenting to the Ladysmith Provincial Hospital over a 44-month period with a diagnosis of ACS. Findings were described and compared.

Results

The mean (SD) age of study patients was 55.8 (±12.8) years. The majority of subjects were male (n=90, 56.3%) and unemployed (n=98, 62.3%). The racial distribution of the study sample comprised 103 (64.4%) Indian, 36 (22.5%) Black, and 21 (13.1%) White subjects. Compared to non-Indian subjects, a significantly higher proportion (p<0.05) of Indian subjects were male (64.7% vs 41.4%), cigarette smokers (52.0% vs 32.8%), had a previous history of ACS (37.3% vs 10.3%), were diabetic (33.3% vs 17.2%), and were hypertensive (58.8% vs 29.3%).

Conclusion

The disproportionately high frequency of ACS among the minority Indian population of Ladysmith is concerning. There is a need for rigorous public health interventions to create local awareness, encourage lifestyle modification, and thereby improve control of cardiovascular risk factors, especially among high-risk population groups.

Wellens Syndrome: An Atypical Presentation With Burning Chest and Epigastric Pain

Wellens syndrome is a pre-infarction stage due to the critical stenosis of the proximal left anterior descending artery. It is characterized by intermittent chest pain with classical ECG changes. The cardiac biomarker is within the normal limit or only slightly elevated in this condition. Early recognition and cardiac intervention are important to prevent adverse cardiac outcomes. We report this rare case of Wellens syndrome in a 70-year-old male with intermittent chest and epigastric pain associated with belching for five days. The patient presented characteristic T-wave changes, symmetric deeply inverted T-waves, in precordial leads (V2-V4). Cardiac biomarkers, including troponin, were negative. He underwent cardiac catheterization and found a clot in the proximal left anterior descending coronary artery, which required a catheter-directed thrombectomy and drug-eluting stent placement. It is important to recognize this condition early and referred on time from primary health centers to higher centers, especially in developing countries like the Maldives, since delays in transfer may lead to a serious outcome.

Early Q-wave morphology in prediction of reperfusion success in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention - A cardiac magnetic resonance imaging study

BACKGROUND

Pathological Q-wave (QW) in the electrocardiogram (ECG) before primary percutaneous coronary intervention (primary PCI) is a strong prognostic marker in patients with ST-segment elevation myocardial infarction (STEMI). However, current binary QW criteria are either not clinically applicable or have a lack of diagnostic performance. Accordingly, we evaluated the association between duration, depth and area of QW and markers of the effect of reperfusion (reperfusion success).

METHODS

A total of 516 patients with their first STEMI had obtained an ECG before primary PCI and an acute cardiac magnetic resonance imaging (CMR) at day 1 (interquartile range [IQR], 1-1) and at follow-up at day 92 (IQR, 89-96). The largest measurable QW in ECG was used for analysis of duration, depth and area of QW (QW morphology). The QW morphology was evaluated as a continuous variable in linear regression models and as a variable divided in four equally large groups.

RESULTS

The QW morphology as four equally large groups was significantly associated with all CMR endpoints (p ≤ 0.001) and showed a linear relationship (p ≤ 0.001) with final infarct size (for QW duration, β = 0.47; QW depth, β = 0.41 and QW area, β = 0.39), final infarct transmurality (for QW duration, β = 0.36; QW depth, β = 0.26 and QW area, β = 0.23) and final myocardial salvage index (for QW duration, β = -0.34; QW depth, β = -0.26 and QW area, β = -0.24).

CONCLUSION

Although modest, the QW morphology in STEMI patients showed significant linear association with markers of reperfusion success. Hence, it is suggested that the term pathological is not used as a dichotomous parameter in patients with STEMI but rather evaluated on the basis of extent.

Atrial Repolarization Waves (Ta) Mimicking Inferior Wall ST Segment Elevation Myocardial Infarction in a Patient with Ectopic Atrial Rhythm

We present a case of atrial repolarization waves from an ectopic atrial rhythm mimicking inferior ST segment elevation myocardial infarction in a 78-year-old male patient who presented with left sided chest wall and shoulder pain. His ischemic workup was negative, and the ST elevations completely resolved upon the resumption of sinus rhythm before discharge.

Electrocardiographic scores of severity and acuteness of myocardial ischemia predict myocardial salvage in patients with anterior ST-segment elevation myocardial infarction

BACKGROUND

Terminal "QRS distortion" on the electrocardiogram (ECG) (based on Sclarovsky-Birnbaum's Grades of Ischemia Score) is a sign of severe ischemia, associated with adverse cardiovascular outcome in ST-segment elevation myocardial infarction (STEMI). In addition, ECG indices of the acuteness of ischemia (based on Anderson-Wilkins Acuteness Score) indicate myocardial salvage potential. We assessed whether severe ischemia with or without acute ischemia is predictive of infarct size (IS), myocardial salvage index (MSI) and left ventricular ejection fraction (LVEF) in anterior versus inferior infarct locations.

METHODS

In STEMI patients, the severity and acuteness scores were obtained from the admission ECG. Based on the ECG patients were assigned with severe or non-severe ischemia and acute or non-acute ischemia. Cardiac magnetic resonance (CMR) was performed 2-6days after primary percutaneous coronary intervention (pPCI). LVEF was measured by echocardiography 30days after pPCI.

RESULTS

ECG analysis of 85 patients with available CMR resulted in 20 (23%) cases with severe and non-acute ischemia, 43 (51%) with non-severe and non-acute ischemia, 17 (20%) with non-severe and acute ischemia, and 5 (6%) patients with severe and acute ischemia. In patients with anterior STEMI (n=35), ECG measures of severity and acuteness of ischemia identified significant and stepwise differences in myocardial damage and function. Patients with severe and non-acute ischemia had the largest IS, smallest MSI and lowest LVEF. In contrast, no difference was observed in patients with inferior STEMI (n=50).

CONCLUSIONS

The applicability of ECG indices of severity and acuteness of myocardial ischemia to estimate myocardial damage and salvage potential in STEMI patients treated with pPCI, is confined to anterior myocardial infarction.

Wellen's syndrome: An ominous EKG pattern

Wellen's syndrome is a characteristic T-wave on an electrocardiogram during a pain-free period in a patient with intermittent chest pain. This finding suggests a high-degree stenosis of the proximal left anterior descending (LAD) coronary artery that will soon result in an acute anterior wall myocardial infarction (MI) if the patient is not urgently catheterized and the occlusion opened. This case report discusses a young male patient with no known cardiac disease with an EKG that demonstrates the classic Wellen's T-waves. He was urgently taken to cardiac catheterization and his 95% proximal LAD stenosis was reduced via drug-eluding stent. Through knowledge of Wellen's T-waves, more anterior wall MIs can be prevented.

Management of acute coronary syndromes in Mexico: gaps and opportunities to improve outcomes

Acute coronary syndromes (ACS) include unstable angina, non-ST-segment elevation myocardial infarction (NSTEMI), and ST-segment elevation myocardial infarction (STEMI). The management of ACS has improved greatly over the last 3 decades, with an associated steady decline in mortality from this condition seen in the US. The benefits of advances in the management of ACS observed in the US have not fully extended to Mexico, as thrombolytic therapy remains the most commonly used reperfusion strategy for STEMI and new antithrombotic drugs are not widely available. However, treatment of ACS in Mexico is rapidly evolving. Dual oral antiplatelet therapy with the combination of clopidogrel and aspirin (acetylsalicylic acid) is becoming the new standard of care for the management of patients with NSTEMI and those undergoing percutaneous coronary intervention. Results from controlled clinical studies strongly support the use of early and aggressive treatment with this combination. The addition of clopidogrel to the national formulary represents an important step in the evolution of care for ACS patients in Mexico. Local and regional leadership is required to foster the widespread adoption of this highly beneficial treatment strategy. The main objectives of this review are to highlight the recommendations of the Mexican guidelines for the management of ACS and provide some perspective regarding challenges to optimal management of ACS patients in Mexico.

Detection of non-ST-elevation myocardial infarction using magnetocardiogram: new information from spatiotemporal electrical activation map

BACKGROUND AND AIM

Non-ST-segment elevation myocardial infarction (NSTEMI) cannot be easily detected in the emergency room. We evaluate a method to detect NSTEMI using 64-channel magnetocardiography (MCG).

METHODS

MCG recordings were made in 20 NSTEMI patients (aged 59.7+/-12.4 years), 15 young (aged 26.8+/-3.4 years), and 13 age-matched control subjects (aged 57.3+/-3.6). We evaluated three approaches to analysis, including 1) determination when individual subjects' MCG results fell outside normal ranges for ten MCG parameters, 2) the magnetic field map at the T-wave peak (T-MFM), and 3) a pair of spatiotemporal activation graphs (STAGs) showing two projections of electrical excitation during repolarization.

RESULTS

Significant differences were found between normal controls and patients for all MCG parameters. None of the healthy controls had more than four MCG abnormal parameters, whereas 19 NSTEMI patients (95%) were abnormal in more than four parameters. STAGs and T-MFM also showed clear differences between healthy controls and NSTEMI patients.

CONCLUSIONS

These results suggest that the MCG is sensitive to changes in the cardiac electrical pathway after myocardial infarction as described by these graphs and parameters, and therefore MCG may be a useful tool to detect severe ischemic patients.

Alarming ST-segment elevation in a young male with left anterior descending coronary artery myocardial bridging

Chest pain continues to be one of the leading emergency department presentations. Acute coronary syndrome is the most dreaded chest pain scenario, as "time is myocardium" in this situation. Numerous benign and less life-threatening diseases like early repolarization, acute pericarditis, and vasospastic angina can present with a similar clinical picture. ST-segment elevation on an electrocardiogram can occur in all these situations and in many others, creating diagnostic dilemma. A young male with chest pain and concurrent ST-segment elevation was reported. He was ultimately discovered to have myocardial bridging of a coronary arterial segment.