Page 100 - Cardiac abnormalities after aneurysmal subarachnoid hemorrhage

Chapter 7
Left ventricular dysfunction
In addition to the ECG abnormalities described above, left ventricular systolic dysfunction has been described in patients with aSAH. Pollick et al.31 provided the first evidence for this in an echocardiographic study. However, as with de ECG data, epidemiological data on the occurrence of the LV dysfunction are conflicting. This may be due to the retrospective nature of most echocardiographic studies, the timing of the echocardiogram, and the difference in study population. Cardiac dysfunction not only occurs immediately after the onset of aSAH, but may also present several days after the aSAH. Pathophysiological data are lacking but this late dysfunction may be provoked by the initial aSAH as troponin may be elevated in patients with late onset dysfunction. Another possibility is that late cardiac dysfunction is caused by delayed cerebral ischemia, or recurrent bleeding (‘rebleeds’). The largest prospective study to date was done by Sato et al.32 who performed echocardiography in 715 patients with aSAH. They found left ventricular dysfunction in 9.4% of the patients. This percentage might be underestimated because the authors only included patients with echocardiographic abnormalities on presentation to hospital. Patients with a normal LV function were not included in the study thus introducing selection bias. Another interesting observation is that the distribution of the wall motion abnormalities may vary. Typically, the apex is dyskinetic with a hyperdynamic base (typical Tako- Tsubo), but reversed Tako-Tsubo (hyperkinetic apex and akinetic base), midventricular Tako-Tsubo (hyperdynamic apex and base but hypokinetic midventricular portion of the myocardium), global hypokinesia or other segmental wall motion abnormalities have also been observed. The wall motion abnormalities usually do not correspond with the perfusion territory of one coronary artery. This makes coronary insufficiency as a cause unlikely. Furthermore, patients that underwent coronary angiograms indeed did not show any occlusion of a coronary artery. Several other studies showed that the wall motion abnormalities are reversible, thus suggesting supportive management in patients with aSAH and myocardial dysfunction. An important strength of the SEAS study is the prospective and consecutive nature and the serial echocardiography. We found that left ventricular dysfunction occurs frequently and that it is reversible. It presents at different time intervals after the onset of the aSAH and it is associated with poor outcome independent of other clinical variables (Chapters 3 and 4).
Myocardial damage and biochemical changes
Although many of the electrocardiographic and echocardiographic abnormalities following aSAH are typically those seen with myocardial ischemia from coronary
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