Syncope: Clinical (To be retired)


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Syncope: Clinical (To be retired)



Advanced cardiac life support (ACLS): Clinical (To be retired)

Supraventricular arrhythmias: Pathology review

Ventricular arrhythmias: Pathology review

Heart blocks: Pathology review

Coronary artery disease: Clinical (To be retired)

Heart failure: Clinical (To be retired)

Syncope: Clinical (To be retired)

Pericardial disease: Clinical (To be retired)

Infective endocarditis: Clinical (To be retired)

Valvular heart disease: Clinical (To be retired)

Cardiomyopathies: Clinical (To be retired)

Hypertension: Clinical (To be retired)

Hypercholesterolemia: Clinical (To be retired)


Cholinomimetics: Direct agonists

Cholinomimetics: Indirect agonists (anticholinesterases)

Sympathomimetics: Direct agonists

Muscarinic antagonists

Sympatholytics: Alpha-2 agonists

Adrenergic antagonists: Presynaptic

Adrenergic antagonists: Alpha blockers

Adrenergic antagonists: Beta blockers

ACE inhibitors, ARBs and direct renin inhibitors

Thiazide and thiazide-like diuretics

Calcium channel blockers

Adrenergic antagonists: Beta blockers

cGMP mediated smooth muscle vasodilators

Calcium channel blockers

Adrenergic antagonists: Beta blockers

Class I antiarrhythmics: Sodium channel blockers

Class II antiarrhythmics: Beta blockers

Class III antiarrhythmics: Potassium channel blockers

Class IV antiarrhythmics: Calcium channel blockers and others

Lipid-lowering medications: Statins

Lipid-lowering medications: Fibrates

Miscellaneous lipid-lowering medications

Positive inotropic medications

Loop diuretics

Antiplatelet medications


Syncope: Clinical (To be retired)

USMLE® Step 2 questions

0 / 3 complete


USMLE® Step 2 style questions USMLE

of complete

A 76-year-old man comes to the office because of a brief loss of consciousness 2 hours ago. He was having dinner with two friends when he looked "pale" and slumped in his chair. He regained consciousness after about two minutes. He has a history of  hypertension and coronary artery disease, which has been treated with two stents. His temperature is 36.8°C (98°F), pulse is 145/min, respirations are 18/min, and blood pressure is 90/68 mm Hg. Cardiac auscultation shows no murmurs. An ECG is obtained and the rhythm strip is shown below. Which of the following is the most likely diagnosis?


Content Reviewers

Rishi Desai, MD, MPH


Antonella Melani, MD

Gil McIntire

Tanner Marshall, MS

Justin Ling, MD, MS

Syncope, or fainting, is when a person loses consciousness and muscle strength. It usually comes on quickly, doesn’t last long, and there’s usually a spontaneous recovery requiring no resuscitation.

It’s caused by a decrease in blood flow to the brain, usually due to low blood pressure.

There’s also presyncope, which is near loss of consciousness with lightheadedness, muscular weakness, blurred vision, and feeling faint without actually fainting.

Presyncope can lead to syncope, so you can think of it as a spectrum of the disease.

Recognizing symptoms of presyncope may allow to act fast and prevent evolution of the episode into a full faint.

The immediate treatment of an individuals with syncope or presyncope starts with laying the individual supine, with legs elevated if possible to help venous return to the heart and restore adequate brain perfusion.

Then, you should assess vital signs, namely a pulse and evidence of respiration, to distinguish cardiac arrest from syncope, and call for additional help if needed.

Finally, you should attempt to arouse the individual without trying to raise them up until they’re ready.

Ok so once the individual has regained consciousness, the next step is to identify the cause.

Neurocardiogenic, vasovagal, and reflex syncope are the most common causes of syncope, and this is a benign condition triggered by parasympathetic activation resulting in vagus nerve discharge.

This discharge may in turn be triggered by urination, defecation, coughing, prolonged standing, or a stressful event like seeing blood and needles.



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