Since cardiac output increases in a relatively linear fashion with external power output and stroke volume becomes constant relatively early in exercise, the slope of the heart rate response to exercise represents an index of stroke volume.
The system provides continuous cardiac output data utilizing the heart rate and an index of stroke volume (obtained from the arterial pressure waveform), which is automatically averaged and updated.
Each item is scored from zero (lowest severity) to a maximum of two, three or four (highest severity), and item scores are summed over all items to provide an index of stroke severity that varies from zero (lowest severity) to 42 (highest severity) [ 18].
There is no indication of bias in the indexing of stroke by radiation exposure.
Furthermore, examination of the correlation coefficients between HRQOL and indices of stroke severity revealed a progressive decrease from the physical (rho = 0.77, p < 0.00001) to the spiritual domain (rho = 0.01, p = 0.893, Table 4, Figures 3A and 3B).
The investigators found that norepinephrine significantly increased MAP to a median value of 75 mmHg, which was associated with significant increases in cardiac output and indices of stroke volume and preload.
In diverse cultures, the correlation coefficients between HRQOL and all indices of stroke severity revealed a decremental trend from the physical domain (rho = 0.77, p < 0.00001) to the spiritual domain (rho = 0.01, p = 0.893).
In evaluating more than 10,000 CF-LVAD recipients in the INTERMACS database, Kirklin and colleagues [ 25] found the following risk factors for increased mortality: elder age, female gender, elevated body mass index, history of stroke, renal dysfunction, right heart dysfunction, surgical complexity, implantation for DT, and INTERMACS profile level 1 or 2 status.
For example, the Paris Index of Heat stroke Related Excess Mortality was formulated to warn of mortality increases during heat waves [ 8].
sBP/LVESVI, a relatively load-independent index of left ventricular contractility [ 30], was the only variable that possessed predictive power independent of stroke volume index (in analysis with both absolute and relative changes from baseline).
Cardiac contractility is difficult to assess at the bedside but can be indirectly appreciated by the assessment of the ventricular stroke work index (basically derived from the product of stroke index and MAP) and the ejection fraction obtained by echocardiography [25].
