![]() ![]() ![]() Second (if no reduction in HR by 20% or HR >100 bpm): 0.35 mg/kg (15-25 mg) IV 9.Initial: 0.25 mg/kg (10-20 mg) IV bolus over 2 minutes.Diltiazem: increases refractory of AV node → slows conduction through AV node → decreases ventricular rate.Since the rate is determined by the AV node, drugs that slow AV conduction are used.Indications: immediate rate control to reduce symptoms in stable patient or chronic therapy to prevent symptoms or cardiomyopathy 9.Adenosine can transiently block the AV node to reveal flutter waves and can help diagnose.Flutter has at least as high of a risk for thromboembolic event as AFib → same risk stratification for anticoagulation as in AFib 7.Chronic flutter with RVR can lead to tachycardia-induced cardiomyopathy 4.A rapid ventricular rate decreases the ventricular filling time and, this coupled with asynchronous atrial to ventricular contraction, can lead to heart failure 2.Dyspnea, angina, or palpitations, and less likely hypotension or syncope. ![]() Symptoms are largely dependent on the ventricular rate.Flutter can either be paroxysmal or persistent, and patients can either be asymptomatic or symptomatic.Patients can develop atypical atrial flutter after AFib ablation due to circuits created by scarring.Can occur after starting an antiarrhythmic drug for AFib.Similar risk factors for AFib: pulmonary disease, diabetes, HTN, older age, obesity, and thyrotoxicosis 5.Uncommon to occur in a structurally normal heart or without a predisposing event or preexisting comorbidity.Incidence in the US is 200,000 new cases per year 5.80% of patients with atrial flutter are male 6.ECG will be different than typical/reverse flutter.Typically associated with structural heart disease, cardiac surgery, or ablation 5.Atrial tachycardias that are caused by a reentrant circuit that do not involve the cavotricuspid isthmus but any portion of the atria 5.Positive flutter waves in inferior leads and negative atrial deflections in V1.If re-entry is clockwise, this is “reverse” typical flutter.Negative flutter waves in inferior leads II, III, aVF and positive atrial deflections in V1 4.Circuit typically rotates in a counterclockwise direction → “sawtooth” EKG pattern.The slow area of conduction that sustains the circuit is the cavotricuspid isthmus (tissue located between the IVC and tricuspid annulus) 3.Reentrant arrhythmia due to an impulse that rotates around the right atrium.Ratio of 2:1 is most common and produces a ventricular rate of 150 beats/min.Ventricular rate determined by AV conduction ratio.Atrial rate commonly 300 beats/min but can range between 250-350 bpm 2.Can be irregular if there is an AV block.Narrow, regular-complex tachydysrhythmia due to a single reentrant circuit within the atria. ![]()
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