Mechanical Reperfusion during Acute Myocardial Infarction in a Patient with Dextrocardia
- Volume 18 - Issue 2 - February, 2006
- Posted on: 8/1/08
- 0 Comments
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Case Report. A 53-year-old male with history of hypertension and hypercholesterolemia presented to the emergency room with new-onset chest pain for the last hour. Clinical examination was remarkable for a right-sided point of maximal impulse, with the liver edge palpable at the left side. His initial conventional electrocardiogram (ECG) showed decrease R-wave voltage throughout the precordial leads with ST-elevations in V1 to V3, as well as a negative P-wave in lead I (Figure 1), in contrast to his reversed dextrocardia ECG (changing precordial leads to the right, and flipping limb leads) that showed more prominent ST-elevation extending up to V4 and the usual R-wave progression, as well as positive P-wave in lead I (Figure 2). The initial management of his anterior ST-elevation infarction included aspirin, intravenous nitrates and unfractionated heparin; beta blockers were held due to his bradycardia, and the patient was taken to the cardiac catheterization laboratory for emergent intervention. Cardiac catheterization was performed via the left common femoral artery using a 6 Fr introducer. His aortic pressure was 133/72/99 mmHg. The anatomical left coronary artery (LCA), right-sided, was cannulated by advancing a 6 Fr Left Judkins 5 cm (JL 5) catheter in the anteroposterior (AP) projection. The anatomical right coronary artery (RCA), left-sided, was cannulated with a 6 Fr Amplatz Right 1 (AR1) catheter. The AP and the right anterior oblique (RAO) projection (30 degrees, with cranial 30 degrees) showed a total proximal to mid-LAD occlusion (right after the first diagonal and septal perforator) (Figure 3), with luminal irregularities evident in the other vessels. The RCA was a dominant vessel. We proceeded with intervention to open the totally occluded LAD. The introducer was exchanged for an 8 Fr, and the LAD was cannulated using an 8 Fr JL 5 guiding catheter. The lesion was crossed using a 0.014 inch Hi-Torque Floppy wire and was predilated with an ACS Photon 3.5 mm x 20 mm balloon using 8 atm for 2 minutes. The lesion site was then stented with a 4.0 x 16 NIR stent using 10 atm for 1 minute (Figure 4). Postdeployment, further dilatation was performed using a 4.5 x 9 mm CHUBBY Balloon with optimal results and 0% residual stenosis (Figure 5).
The patient had an excellent clinical course with complete resolution of the ST-segments in his ECG(Figure 6), and he left the hospital on clopidogrel, aspirin, an ACE inhibitor and a statin.
Primary angioplasty and upfront stenting have become the preferred mode of reperfusion in acute myocardial infarction. Patients with dextrocardia and situs inversus are rare, however, they maintain the same incidence of myocardial infarction.
The most common form of dextrocardia is known as mirror-image, in which the anatomic right ventricle is anterior to the left ventricle and the aortic arch curves to the right and posteriorly. The ECG shows negative P-waves in lead I (right-axis deviation of the P-wave), and the QRS complex with low voltage in the left precordial leads and poor R-wave progression, as well as a reversal in leads II and III (indicating left-to-right activation with right axis deviation). This pattern can be reversed to normal by changing the positioning of the electrodes (reversed dextrocardia), which in our case, revealed the true extent of jeopardized myocardium.
Our report shows a successful primary percutaneous coronary intervention (PCI) using upfront stenting of the LAD, and no difficulty using standard catheters for cannulation of the coronary arteries by rotating the catheters in the opposite direction (i.e., counter-clockwise with AR1 catheter to cannulate the left-sided anatomical RCA). Contrary to what other authors have suggested, we also worked with standardized image acquisition without problems once the anatomic orientation was understood, hence there was no need for right-to-left image reversal.
Furthermore, the classical findings of a mirror image dextrocardia case during an acute ST-segment elevation anterior wall myocardial infarction was better estimated by the use of reversed dextrocardia ECG with complete resolution of the ST-elevation post-primary PCI as an excellent indicator of reperfusion beyond the epicardial vessels.
This report confirms the utilization of a conventional modern technique for mechanical revascularization in patients with dextrocardia and situs inversus and shows a clear anatomic and electrocardiographic correlation for successful myocardial reperfusion.