Radial Strain: Harbinger of Good News.

INTRODUCTION: We report the case of a 58-year-old woman with intracranial hemorrhage associated with stress-induced cardiomyopathy.
RESULTS: Left ventricular dysfunction was confined to midventricular segments, and manifested with transient anterolateral wall aneurysm. Although wall motion was severely impaired in the mid-segments, an almost preserved global midventricular radial strain forecasted rapid improvement of ventricular function.
CONCLUSIONS: This case highlights how deformation imaging can help in clinical practice to interpret the subtle signs of recovery from left ventricular dysfunction.

CASE REPORT

A 58-year-old woman was admitted one year ago to the neurointensive care unit of our hospital for sudden onset of intracerebral and subarachnoid hemorrhage of the right frontal lobe. She had a history of tobacco use and moderate alcohol abuse, hypertension and chronic obstructive pulmonary disease. Her surgical history included left lumpectomy for breast cancer, amputation of the third finger on the right hand and jaw surgery a few years ago. At admission her vital signs were within the normal range: blood pressure 140/87 mmHg, heart rate 71 beats per minute (bpm), respiratory rate 20 breaths per minute and oxygen saturation on ventilator 100%. She was awake and alert but lethargic. The electrocardiogram (ECG) at admission showed normal sinus rhythm (60 bpm) and possible septal necrosis. Right craniotomy for evacuation of the hemorrhage and clipping of right middle cerebral artery aneurysm were performed. Postoperatively, her neurological functions were intact. Troponin I levels showed a slight increase from 0.33 to 3.55 ng/mL during the first two days, and then decreased to 1.96 ng/mL on the third day postsurgery, and similar variations were seen for the levels of creatine kinase-MB fraction (from 4.0 to 11.5 to 4.3 μmol/L). ECG on the second day showed deep negative T waves in almost all leads with prolonged QTc interval [Figure 1]. Due to abnormal myocardial necrosis markers and ECG, a two-dimensional (2D) transthoracic echocardiogram was ordered, and revealed a normal left ventricular cavity size with hyperdynamic basal motion, akinesis of midventricular segments and nearly normal apical motion [Figure 2]. Left ventricular global systolic function was moderately decreased with left ventricular ejection fraction at 35% (normal values >55%). Clinical and echocardiographic features were consistent with stress-induced cardiomyopathy.

Figure 1

Electrocardiogram on second day post-right craniotomy for evacuation of hemorrhage and clipping of right middle cerebral artery aneurysm showing deep negative T waves in almost all leads with prolonged QTc interval (580 ms)

Figure 2

Two-dimensional transthoracic echocardiography in the apical four-chamber view showing the left ventricle a) at end diastole and b) mid-systole. Basal and apical segments contract well in contrast to midventricular segments

The next day, the patient underwent coronary angiography, which ruled out any coronary artery disease. However, the ventriculogram surprisingly revealed an aneurysmatic anterior wall [Figure 3], which then was characterized by another transthoracic echocardiogram as an anteroseptal wall aneurysm with near-normal motion of the other segments [Figure 4]. Global radial strain was calculated and, despite seriously compromised midventricular anteroseptal motion, midventricular-averaged radial strain was at the lower end of normal range (i.e. 16%).

Figure 3

Left ventriculogram showing systolic anterior wall aneurysm

Figure 4

Two-dimensional transthoracic echocardiography in the apical long-axis view showing anteroseptal wall aneurysm with nearly normal motion of the other segments in a) end diastole and b) mid-systole

As predicted by the global radial strain in the previous examination, another transthoracic echocardiogram performed three weeks later documented the complete resolution of wall motion abnormalities [Figure 5a and b], with completely normal radial strain values [Figure 5c].

Figure 5

Two-dimensional (2D) transthoracic echocardiogram in the apical long-axis view showing complete resolution of wall motion abnormalities at a) end diastole and b) mid-systole. c) shows radial strain of midventricular segments. On the left, a short-axis view of the mid-left ventricle is shown, and a 2D speckle tracking technique is used to obtain the curves representing radial deformation of each wall segment (right). The averaged global strain is 57% (represented by white curve)

DISCUSSION

Isolated left ventricular midventricular dyskinesia is a rare variant of stress-induced cardiomyopathy,[1] although it has been described in association with cerebral injuries.[2] Left ventricular mechanics in stress-induced cardiomyopathy have not been well defined, although some data about the longitudinal and radial strain are available.[3]

CONCLUSIONS

Our case highlights the importance of global radial strain as a predictor of myocardial wall motion improvement, even when 2D transthoracic echocardiogram did not forecast the improvement.