Percutaneous coronary intervention: cardiogenic shockBMJ 2003; 326 doi: https://doi.org/10.1136/bmj.326.7404.1450 (Published 26 June 2003) Cite this as: BMJ 2003;326:1450
- John Ducas, consultant cardiologist, associate professor,
- Ever D Grech, consultant cardiologist, assistant professor
- Health Sciences Centre and St Boniface Hospital, Winnipeg, Manitoba, Canada, University of Manitoba, Winnipeg.
- Health Sciences Centre and St Boniface Hospital, University of Manitoba.
Cardiogenic shock is the commonest cause of death after acute myocardial infarction. It occurs in 7% of patients with ST segment elevation myocardial infarction and 3% with non-ST segment elevation myocardial infarction.
Cardiogenic shock is a progressive state of hypotension (systolic blood pressure < 90 mm Hg) lasting at least 30 minutes, despite adequate preload and heart rate, which leads to systemic hypoperfusion. It is usually caused by left ventricular systolic dysfunction. A patient requiring drug or mechanical support to maintain a systolic blood pressure over 90 mm Hg can also be considered as manifesting cardiogenic shock. As cardiac output and blood pressure fall, there is an increase in sympathetic tone, with subsequent cardiac and systemic effects—such as altered mental state, cold extremities, peripheral cyanosis, and urine output < 30 ml/hour.
Effects of cardiogenic shock
In an attempt to maintain cardiac output, the remaining non-ischaemic myocardium becomes hypercontractile, and its oxygen consumption increases. The effectiveness of this response depends on the extent of current and previous left ventricular damage, the severity of coexisting coronary artery disease, and the presence of other cardiac pathology such as valve disease.
Three possible outcomes may occur:
Compensation—which restores normal blood pressure and …