arrhythmias/multifocal atrial tachycardia

See Explanation

[ "https://i.postimg.cc/3wMvTJH5/case-102954-image-1-matiii.jpg" ]

Question 1 / 3

683c98b6bf0c2b5ee08e4a4d

Cardiology

arrhythmias

multifocal atrial tachycardia

Case History

An active 78-year-old woman with a history of chronic obstructive pulmonary disease, essential hypertension, and recurrent bronchitis presents to an outpatient clinic with increasing shortness of breath and a sensation of her heart racing over the past few hours. She reports persistent cough productive of clear sputum. On examination, her temperature is 37.90C, blood pressure is 162/95 mm Hg, pulse is irregularly irregular at 135 beats/min, respiratory rate is 24 breaths/min, and oxygen saturation is 88% on room air. Her cardiac exam reveals a rapid, irregular rhythm with no murmurs. Pulmonary auscultation reveals diffuse crackles and scattered expiratory wheezes throughout both lung fields. There is no peripheral edema. An electrocardiogram is obtained, displaying varying P-wave morphologies and irregular R-R intervals. Given this patient's presentation, what is the most likely cardiac arrhythmia and the appropriate initial pharmacologic intervention?

Lab Parameter	Value	Reference Range
White Blood Cell Count	13.2 x 10^9/L	4.0-11.0 x 10^9/L
Potassium	4.1 mmol/L	3.5-5.0 mmol/L
Magnesium	0.95 mmol/L	0.75-1.05 mmol/L
Arterial pH	7.32	7.35-7.45
Arterial pCO2	58 mmHg	35-45 mmHg
Arterial pO2	62 mmHg	75-100 mmHg

A ) Multifocal Atrial Tachycardia and Amiodarone administration

B ) Atrial Fibrillation with Rapid Ventricular Response and Digoxin therapy

C ) Multifocal Atrial Tachycardia and Diltiazem administration

D ) Atrial Flutter with Rapid Ventricular Response and Metoprolol therapy

E ) Supraventricular Tachycardia (unspecified) and Adenosine bolus

Edit question

See Explanation

[ "https://i.postimg.cc/tRWfD0ZJ/case-214389-image-1-mat.jpg" ]

Question 2 / 3

683c98b6bf0c2b5ee08e4a4e

Cardiology

arrhythmias

multifocal atrial tachycardia

Case History

A 68-year-old man, with a significant history of severe chronic obstructive pulmonary disease (COPD) requiring home oxygen and chronic heart failure with preserved ejection fraction, is admitted to the hospital with acute on chronic respiratory distress. He reports a several-day history of increasing cough productive of purulent sputum, exertional dyspnea, and orthopnea. His wife notes he has become increasingly confused. On examination, he is lethargic but arousable. His temperature is 37.8°C (100.0°F), blood pressure is 148/88 mmHg, pulse is 128 beats/min and irregularly irregular, respiratory rate is 26 breaths/min, and oxygen saturation is 88% on 2 L/min nasal cannula. Pulmonary auscultation reveals diffuse expiratory wheezes and coarse inspiratory crackles bilaterally. He has 2+ pitting edema to his mid-shins and jugular venous distension up to 10 cm above the sternal angle. An ECG obtained on admission shows a rapid, irregularly irregular rhythm with at least three distinct P wave morphologies and varying PR and RR intervals, consistent with multifocal atrial tachycardia (MAT). Considering his overall clinical status and the ECG findings, what is the most appropriate immediate management strategy and a potential acute complication if not adequately addressed?

Lab Parameter	Value	Reference Range
White Blood Cell Count	14.5 x 10^9/L	4.0-11.0 x 10^9/L
Hemoglobin	138 g/L	130-170 g/L
Potassium	3.2 mmol/L	3.5-5.0 mmol/L
Magnesium	0.70 mmol/L	0.75-1.05 mmol/L
Arterial pH	7.28	7.35-7.45
PaCO2	62 mmHg	35-45 mmHg
PaO2	58 mmHg	80-100 mmHg
Bicarbonate (HCO3-)	29 mmol/L	22-26 mmol/L

A ) Aggressive bronchodilator therapy with intravenous corticosteroids and loop diuretics; potential complication: severe metabolic alkalosis

B ) Intravenous metoprolol for rate control and urgent synchronized electrical cardioversion; potential complication: worsening bronchospasm leading to respiratory failure

C ) Optimize oxygenation, correct electrolyte imbalances, and treat underlying COPD exacerbation; potential complication: persistent arrhythmia and decompensated heart failure

D ) Initiate amiodarone infusion for rhythm control and full anticoagulation with unfractionated heparin; potential complication: pulmonary fibrosis and bleeding

E ) Administer intravenous digoxin for rate control and obtain serial troponin levels; potential complication: digoxin toxicity and myocardial ischemia

Edit question

See Explanation

[]

Question 3 / 3

683c98b6bf0c2b5ee08e4a4f

Cardiology

arrhythmias

multifocal atrial tachycardia

Case History

A 72-year-old woman with a long-standing history of severe chronic obstructive pulmonary disease (COPD) and recent upper respiratory infection symptoms presents to the emergency department after being brought by her family. She reports progressive dyspnea over the past 48 hours, now so severe she can only speak a few words at a time. Her family mentions she has been more lethargic and her home oxygen saturation readings have been declining. On examination, she appears distressed, using accessory muscles to breathe, and has diminished breath sounds bilaterally with diffuse expiratory wheezes. Her vital signs are: Temperature 37.8°C, Blood Pressure 100/65 mmHg, Heart Rate 125 bpm, Respiratory Rate 28 breaths/min, and Oxygen Saturation 84% on room air. An electrocardiogram reveals a narrow-complex tachycardia with an irregularly irregular rhythm. Closer inspection shows at least three distinct P wave morphologies, with varying PR intervals, and an atrial rate of approximately 130 beats per minute. Given these findings, what is the most likely diagnosis and the immediate critical management step?

Lab Parameter	Value	Reference Range
White Blood Cell Count	14.5 x 10^9/L	4.0-11.0 x 10^9/L
Hemoglobin	135 g/L	120-150 g/L
Platelets	280 x 10^9/L	150-450 x 10^9/L
Sodium	138 mmol/L	135-145 mmol/L
Potassium	3.2 mmol/L	3.5-5.0 mmol/L
Creatinine	90 µmol/L	44-106 µmol/L
Glucose	8.5 mmol/L	3.9-6.1 mmol/L

A ) Diagnosis of Atrial Fibrillation and administration of intravenous diltiazem for rate control.

B ) Diagnosis of Sinus Tachycardia and initiation of empiric antibiotic therapy for presumed pneumonia.

C ) Diagnosis of Multifocal Atrial Tachycardia and immediate high-flow supplemental oxygen therapy with close monitoring.

D ) Diagnosis of Atrial Flutter and preparation for electrical cardioversion.

E ) Diagnosis of Multifocal Atrial Tachycardia and immediate intubation for airway protection.

Edit question