00:00 / 00:00
Bundle branch block
Pulseless electrical activity
Atrioventricular nodal reentrant tachycardia (AVNRT)
Premature atrial contraction
Long QT syndrome and Torsade de pointes
Premature ventricular contraction
Coronary steal syndrome
Coarctation of the aorta
Polycystic kidney disease
Renal artery stenosis
Peripheral artery disease
Subclavian steal syndrome
Superior mesenteric artery syndrome
Human herpesvirus 8 (Kaposi sarcoma)
Chronic venous insufficiency
Deep vein thrombosis
Acyanotic congenital heart defects: Pathology review
Aortic dissections and aneurysms: Pathology review
Atherosclerosis and arteriosclerosis: Pathology review
Cardiac and vascular tumors: Pathology review
Cardiomyopathies: Pathology review
Coronary artery disease: Pathology review
Cyanotic congenital heart defects: Pathology review
Dyslipidemias: Pathology review
Endocarditis: Pathology review
Heart blocks: Pathology review
Heart failure: Pathology review
Hypertension: Pathology review
Pericardial disease: Pathology review
Peripheral artery disease: Pathology review
Shock: Pathology review
Supraventricular arrhythmias: Pathology review
Valvular heart disease: Pathology review
Vasculitis: Pathology review
Ventricular arrhythmias: Pathology review
0 / 13 complete
0 / 2 complete
β -blockers for p. 329
ECG tracing of p. 300
potassium channel blockers for p. 329
The heart has four chambers, two upper chambers—the left and right atrium, or together the atria, and two lower chambers—the left and right ventricles.
Well there’s a wave of muscle contraction that flows through the atria that looks like its flapping or fluttering, hence the name.
Usually, that signal moves in one direction from the atria to the ventricles through the AV node, it then moves down to the ventricles, and causes them to contract shortly after.
Reentrant signals loop back on themselves, overriding the sinus node and setting up an endless cycle that causes the atria to contract again and again and again—at really fast rates.
There are actually two types, type 1 or typical atrial flutter is more common and is caused by a single reentrant circuit that moves around the annulus, or the ring of the tricuspid valve of the right atrium, usually in a counterclockwise direction when viewed looking up through the tricuspid valve.
In this case, a stretch of tissue along the pathway called the cavotricuspid isthmus propagates the signal more slowly than the surrounding tissue.
Tissue that was just activated can’t be activated again until a certain amount of time has passed, which is called the refractory period; so that slow propagation gives the tissue enough time to be out of refractory, and therefore the circuit can loop on itself.
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