Today, in cardiology, acute coronary syndrome (ACS) is one of the most common presentations in hospitals. Usually, the history and presenting features of ACS are very typical. However, some patients have an atypical presentation, which can pose a problem for prompt diagnosis and management, leading to an overall increase in morbidity and mortality in such patients.
A 61-year-old man with no previous medical history of, or risk factors for, coronary artery disease was admitted to hospital via the accident and emergency department with a one-day history of severe occipital headache along with weakness and numbness of the left arm. On admission, his electrocardiograms (ECGs) showed significant ST segment elevation in inferior leads along with reciprocal ST segment depression in lateral leads, developing Q waves afterwards. In view of the clinical presentation, these ECG changes were ignored and the patient underwent investigations as a likely case of subarachnoid haemorrhage (SAH) under the care of the on call physician. He underwent an urgent computed tomography (CT) brain scan followed by lumbar puncture, both of which were negative for SAH.
The next day, the patient was referred to cardiology for investigation of his ECG changes. By that time, his ECGs had developed deep Q waves in inferior leads and the ST segments were starting to settle (see Figure 1). He also had a significant rise in troponin levels (high sensitive troponin T greater than 2,000 pg/ml). In view of his atypical presentation, he underwent, on the same day, a CT angiogram of the head and neck, which did not show any evidence of dissection of the aorta or of any head and neck vessels. An urgent transthoracic echocardiogram carried out the same day confirmed a reduced left ventricular systolic function along with extensive inferior wall akinesia as well as septal and posterior wall hypokinesia.
The patient was treated, as per the protocol for acute coronary syndrome (ACS), with fractionated heparin, dual antiplatelets, beta-blocker, angiotensin-converting enzyme inhibitor, statin and eplerenone (a potassium-sparing diuretic). His cardiac catheterisation was delayed, as he developed post-myocardial infarction (MI) Dressler’s syndrome, which was treated with non-steroidal anti-inflammatory drugs. A dobutamine stress echocardiogram performed in the interim confirmed inferior infarction with evidence of myocardial viability and reversible myocardial ischaemia in the inferior, septal, posterior and lateral walls of the left ventricle. Left heart catheterisation confirmed three-vessel coronary artery disease with proximally occluded dominant right coronary artery (see Figure 2), along with severe ostial disease in the left anterior descending, diagonal and left circumflex branches (see Figures 3 and 4). A left ventricular angiogram showed significant inferior wall akinesia along with moderate impairment of the left ventricular systolic function (see Figure 5). The patient subsequently underwent inpatient coronary artery bypass grafting, with grafts to the right, left anterior descending, left circumflex and marginal coronary arteries. Post-operative recovery was uneventful and the patient successfully underwent cardiac rehabilitation.
In this case of ACS, the potential differential diagnoses were:
- acute SAH;
- Takotsubo cardiomyopathy; and
- left ventricular non-compaction cardiomyopathy.
SAH patients have often been misdiagnosed as having cardiac abnormalities based on their ECGs when, in many instances, the ECG changes were the result of the SAH itself. This has led to unnecessary and wasteful investigations and therapies on many occasions.1 Takotsubo cardiomyopathy is reported to present with features mimicking stroke. One of the published case reports mentions the case of a 74-year-old woman with minor stroke as the main clinical presentation of a Takotsubo-like syndrome, due to transient thrombus formation in the left ventricular cavity.2 Left ventricular non-compaction is associated with dysrhythmias, thromboembolic events, chest pain and left ventricular dysfunction.3 Stroke itself can sometimes be the presenting feature of left ventricular non-compaction cardiomyopathy.
In patients who could possibly be suffering from ACS, careful interpretation of the ECGs is of utmost importance. A multidisciplinary approach to complicated medical cases should be sought at the earliest opportunity.