Subacute Right Ventricular Perforation by Pacemaker Lead Causing Left-Sided Hemothorax and Epicardial Hematoma

Table 1

	Normal values	Expected change in perforation	Why the parameter may change differently even in perforation
Impedance	400–1000 Ohms	Usually decreased	May increase if the lead ends in an air-filled space
Sensing (R-wave amplitude)	At least 5 mV	Usually decreased	May increase if the lead becomes parallel to the incoming electric current vector
Capture threshold	Less than 1 volt at a pulse width of 0.5 milliseconds	Usually there is loss of capture	May remain the same if the lead has not moved a long distance from the heart