Ultrasound-Guided Pericardiocentesis
All the years of ultrasound training in residency has paid off. You found the large pericardial effusion in the hypotensive patient who is still alive, but looks sick. You are a star! The only problem was that you never performed a pericardiocentesis in an awake patient. The cardiology fellow is at home sleeping and/or the closest receiving hospital is about 1 hour away. Now what?
Dr. Arun Nagdev reviews how to do an ultrasound guided pericardiocentesis as part of this new, ongoing series of advanced ultrasound tips for emergency physicians.
More than one third of patients will have chest pain associated with SVT causing providers to order troponins and other cardiac enzymes. Elevated troponins are not pathognomonic for CAD/ACS and could represent other etiologies such as sepsis, subarachnoid hemorrhage, and pulmonary embolism. Also, subsequent coronary angiography is not necessary for risk stratification in all cases. SVT causes a rapid heart rate, which is well documented as a cause for modest troponin elevation secondary to cardiac stretch, poor diastolic perfusion, and/or coronary artery vasospasm.
Posterior myocardial infarction (MI) represents 3.3 – 21% of all acute MIs and can be difficult to diagnose by the standard precordial leads. Typically, leads V7 – V9 are needed to diagnose this entity. Luckily, leads V1 – V3, directly face the posterior wall of the left ventricle and are the “mirror image” of the posterior wall of the left ventricle.
Differentiating between SVT with aberrancy and VT can be very difficult. It is crucial to be able to make this distinction as therapeutic decisions are anchored to this differentiation. Brugada et al prospectively analyzed 384 patients with VT and 170 patients with SVT with aberrant conduction to see if it was possible to come up with a simple criteria to help differentiate between the two with high sensitivity and specificity.