1. What are peaked T waves?
Peaked T waves typically come from hyperkalemia, either local (from myocyte death, i.e. myocardial infarction) or systemic (elevated serum K for whatever reason) and are defined as abnormally symmetric T waves (usual T wave has gradual upslope and brisk downstroke)that are tall (>10mm in precordial leads, >5mm in limb leads, or abnormally tall compared to prior) with a sharp peak.
2. What are balloon pumps and are they helpful?
Balloon pumps are positioned in the descending thoracic aorta and inflates during diastole. They do two things: 1) augment diastolic pressure (increasing coronary perfusion pressure) and 2) afterload reduction (easing myocardial work and reducing wall tension). They have not been extensively studied due to the inherently ill patient population, and there is conflicting evidence for support of their use. They're mainly indicated in high risk PCI and shock due to MI. In high risk PCI there is evidence to suggest benefit in mortality over time (see the BCIS-1 trial). In cardiogenic shock, there is evidence to suggest no benefit (see the IABP-SHOCK II trial), but this trial has been criticized due to heterogenous patient population (see Am J Cardiol 2016; 117(3): 469-76.).