ECG and Arrythmias
The normal intrinsic pacemaker of the heart that typically fires at 60–100 beats/min.
SA node
A patient with HFrEF has an ejection fraction of 35%. Is the primary problem impaired contraction or impaired relaxation?
Impaired contraction, or systolic dysfunction.
This medication increases cardiac contractility by inhibiting the Na⁺/K⁺-ATPase pump and increasing intracellular calcium.
Digoxin
Which coronary artery supplies much of the anterior left ventricle and anterior septum?
The left anterior descending artery (LAD).
A patient with suspected ACS suddenly becomes unresponsive and has no normal breathing. What is the immediate priority?
Activate emergency response and begin CPR while obtaining an AED or defibrillator.
An ECG rhythm has no distinct P waves and an irregularly irregular ventricular rhythm. Identify the rhythm.
A fib
Crackles, orthopnea, pulmonary edema, and pink frothy sputum indicate which type of heart failure congestion?
Left-sided heart failure with pulmonary congestion.
A patient taking digoxin has nausea, yellow halos, a pulse of 52/min, and potassium of 3.0 mEq/L. What is the priority action?
Hold digoxin, notify the provider promptly, and anticipate ECG, electrolyte, and toxicity evaluation.
This biomarker typically rises within approximately 3 hours, peaks around 12–24 hours, and may remain elevated for 7–10 days.
Cardiac troponin.
A patient with atrial fibrillation develops sudden facial drooping and unilateral arm weakness. What should the nurse do first?
Activate emergency stroke evaluation immediately and determine the last-known-well time.
The PR interval progressively lengthens until a QRS complex is dropped. Identify the conduction disorder
Second-degree AV block, Mobitz I (Wenckebach)
Differentiate preload from afterload and explain how excessive levels can worsen heart failure.
Preload is ventricular filling/stretch before contraction; afterload is resistance to ejection. Excess preload increases congestion, while increased afterload raises wall stress and myocardial oxygen demand.
A patient receiving amiodarone reports a new persistent cough and worsening dyspnea. What toxicity should the nurse suspect?
Pulmonary toxicity, including amiodarone-associated pneumonitis or fibrosis. Prompt evaluation is needed.
Explain why an increased heart rate raises myocardial oxygen demand while also potentially reducing coronary oxygen supply.
Heart rate increases myocardial workload and oxygen consumption while shortening diastole, when most left coronary perfusion occurs.
A patient taking atorvastatin reports severe muscle pain and dark-colored urine. What complication should the nurse suspect?
Statin-associated rhabdomyolysis, which can lead to acute kidney injury. Hold/clarify therapy and notify the provider for urgent evaluation.
A patient has pulseless ventricular tachycardia. What electrical intervention is indicated?
Immediate defibrillation with CPR according to the resuscitation algorithm
A patient with acute pulmonary edema has severe dyspnea, SpO₂ 80%, crackles, and pink frothy sputum. What should the nurse prioritize?
Position high-Fowler's, support oxygenation, activate urgent assistance, and prepare for positive-pressure ventilation and prescribed IV therapy.
A patient taking lisinopril is prescribed sacubitril/valsartan. How long must the patient wait after the final ACE inhibitor dose before starting the ARNI?
At least 36 hours, to reduce the risk of angioedema.
Four days after an MI, a patient suddenly develops pulmonary edema and a new loud holosystolic murmur. Which complication should the nurse suspect?
Papillary muscle rupture causing acute mitral regurgitation. Ventricular septal rupture is another serious post-MI mechanical complication and requires urgent evaluation.
A patient with chest pain reports taking tadalafil earlier today. Why should the nurse withhold prescribed sublingual nitroglycerin?
The combination can cause profound vasodilation and dangerous hypotension. Notify the provider and follow emergency ACS protocols
A patient with complete heart block has a ventricular rate of 26/min, BP 72/40, and altered mental status. What is the priority intervention?
Activate emergency assistance, support ABCs, and prepare for immediate transcutaneous pacing while arranging definitive pacing.
A patient is hypotensive, cold and clammy, oliguric, and has elevated filling pressures after a large MI. Identify the likely type of shock and its pathophysiology.
Cardiogenic shock. Pump failure decreases cardiac output, increases ventricular filling pressures, and triggers compensatory systemic vasoconstriction.
A patient with HFrEF receiving IV milrinone develops hypotension and ventricular ectopy. Explain the medication's therapeutic mechanism and the reason for concern.
Milrinone inhibits PDE-3, increasing cAMP to produce positive inotropy and vasodilation. Hypotension and ventricular dysrhythmias are serious adverse effects requiring immediate assessment and escalation.
A patient with an inferior STEMI develops hypotension, clear lung sounds, and jugular venous distention. What ventricular involvement should the nurse consider, and why?
Right ventricular infarction, often associated with RCA occlusion. Reduced right ventricular pumping decreases pulmonary blood flow and left-sided preload, causing hypotension.
A patient with heart failure taking spironolactone and sacubitril/valsartan has weakness, peaked T waves, and potassium of 6.4 mEq/L. What is the priority nursing response?
Recognize potentially life-threatening hyperkalemia, place the patient on cardiac monitoring, notify the provider/rapid response immediately, and anticipate urgent treatment.