Colours correspond to Class of Recommendation. *Atropine should not be given in patients after heart transplant. †In patients with drug toxicity and severe symptoms, preparation for pacing should proceed simultaneously with pharmacologic treatment of drug toxicity. AADs indicates antiarrhythmic drugs; AV, atrioventricular;BB, beta blocker; CCB, calcium channel blocker; COR, Class of Recommendation;ECG, electrocardiographic; H+P, history and physical examination; IMI, inferior myocardial infarction; IV, intravenous; PM, pacemaker; S/P, status post; and VS, vital signs.
Autonomic derangements during an acute MI are common, and small case series suggest that atropine can be used to increase heart rate. Atropine appears to be safe in those patients with atrioventricular nodal block in the absence of infranodal conduction system disease.
In contrast, it is important to recognize that the use of atropine in patients with infranodal conduction disease or block can be associated with exacerbation of block and is potentially of harm. Aminophylline/theophylline has also been examined in this setting, and in the context of very limited data appears likely to be safe if atropine is ineffective. The methylxanthines theophylline and aminophylline (a theophylline derivative) exert positive chronotropic effects on the heart, likely mediated by inhibition of the suppressive effects of adenosine on the sinoatrial node.
Given that the natural course of a MI with conduction system abnormalities is frequently associated with recovery of conduction – early and unnecessary pacing should be avoided.
Hyperacute T-waves are often the first manifestation of complete vessel occlusion; they are wide, bulky and prominent.
Hyperacute T-waves are not necessarily tall, and small T-waves can still be hyperacute when paired with a low-amplitude QRS complex.
De Winter T-waves represent LAD occlusion (a STEMI equivalent) requiring immediate revascularization.
Previously inverted T-waves can appear normal and upright in the setting of acute vessel occlusion. This is known as pseudonormalization.
The tall T-waves associated with hyperkalemia are sharp, pointy, symmetric, and have a narrow base.
When in doubt, get serial ECGs (every 15 minutes) and use adjunctive information.
Manage Cookie Consent
The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network.
The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user.
The technical storage or access that is used exclusively for statistical purposes.The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you.
The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes.