Displacement of impella post chest compressions.

The Impella is a left ventricular assist device which is implanted via the transcutaneous femoral route and is placed across the aortic valve into the left ventricle. We report an interesting case where cardiopulmonary resuscitation was associated with displacement of Impella device. Impella is being increasingly used these days especially in patients with cardiogenic shock. Clinicians should have high index of suspicion for displacement of Impella in appropriate clinical setting.

INTRODUCTION

Circulatory assist devices are increasingly being used for a wide range of clinical conditions ranging from prophylactic insertion before invasive procedures to cardiogenic shock or cardiopulmonary arrest. The Impella®2.5 device (Abiomed), a left ventricular assist device, is a catheter pump with a maximum axial flow of 2.5 L/min. It is implanted via the transcutaneous femoral route and is placed across the aortic valve into the left ventricle.[1] The pump revolves at high speed drawing blood out of the left ventricle and ejecting it into the ascending aorta resulting in active drainage. We report an interesting clinical scenario associated with the use of Impella.

CASE REPORT

A 49-year-old man with a history of coronary artery disease, multiple percutaneous revascularization procedures, in both the left anterior descending (LAD) and the left circumflex arteries (LCX), presented with complaints of severe retrosternal chest discomfort. His electrocardiogram (ECG) and enzymes supported the diagnosis of an anterolateral myocardial infarction and he was taken emergently to the catheterization lab. Blockage was found in his LAD and LCX and thrombolysis and angioplasty were performed. He developed flash pulmonary edema and was intubated and admitted to the intensive care unit (ICU). He went on to develop atrial fibrillation with rapid ventricular response, ST segment elevations, and increasing troponins overnight and was taken again to the catheterization lab next morning. The arteries were patent, but the left ventricular ejection fraction had dropped to 20%. An Impella device was placed. He was stabilized and returned to the ICU, but later that day the patient went into pulseless ventricular tachycardia. Chest compressions were done with return of spontaneous circulation. Repeat chest X-ray was done post compressions. The X-rays before compression and after compressions are shown in Figure 1.

Figure 1

Displacement of Impella before and after cardiopulmonary resuscitation The tip of Impella can be seen displaced from a fixed anatomical point on anteroposterior chest X-ray images

It was noticed that the Impella device was displaced post chest compressions. Complete metabolic panel and complete blood count were checked along with lactate dehydrogenase (LDH) and haptoglobin, and were significant for elevated LDH 1,554 U/L (normal range 94-250 U/L), reduced haptoglobin 26 mg/dL (30-200 mg/dL). Displacement of the Impella was confirmed with transthoracic echocardiography and was repositioned. Unfortunately, the patient had multiple comorbidities and deteriorated clinically with increasing requirements of vasopressor and inotropes and rising lactate. The family decided to withdraw care and the patient died the next day.

DISCUSSION

The use of Impella devices is surging, with more being used now than any time before. Displacement of the Impella can be a catastrophic complication post chest compressions, resulting in increased intravascular hemolysis and cardiovascular compromise. Displacement of Impella has been rarely reported.[2] With the use of Impella increasing in the last few years, and high predisposition of these patients to require chest compressions, with underlying comorbidities, it is pertinent that these patients have mandatory echocardiography or chest X-ray at least to ensure that Impella has not displaced from its position. Routine measurement of biochemical markers of hemolysis and serial hemoglobin values during Impella device support have also been advocated to allow timely detection and treatment of ongoing hemolysis.[3]