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Zorluk: Çok zorCardiovascular System

A 68-year-old man presents to the clinic for evaluation of progressive shortness of breath, fatigue, and right-sided abdominal discomfort that has worsened over the past three weeks. One month ago, he underwent uncomplicated placement of a dual-chamber transvenous pacemaker for symptomatic third-degree atrioventricular block. His medical history includes severe chronic obstructive pulmonary disease, for which he uses a daily inhaled long-acting muscarinic antagonist and an inhaled corticosteroid-long-acting beta-agonist combination.

Vital signs show a temperature of 37.0∘C37.0^\circ\text{C} (98.6∘F98.6^\circ\text{F}), blood pressure of 115/70 mm Hg115/70\text{ mm Hg}, and a paced pulse of 72/min72\text{/min}. Oxygen saturation is 94%94\% on room air.

Physical examination reveals distended neck veins while sitting at a 45∘45^\circ angle, with a jugular venous pressure of 15 cm H2O15\text{ cm H}_2\text{O} and a prominent, rapid positive wave occurring during ventricular systole. Pulmonary auscultation demonstrates a prolonged expiratory phase with scattered bilateral wheezes. Cardiac examination reveals a regular rate and a grade 3/63/6 blowing holosystolic murmur at the left lower sternal border that becomes louder during inspiration. The liver is enlarged and exhibits a palpable systolic pulsation. There is 2+2+ pitting edema in both lower extremities up to the knees. Laboratory studies show a normal leukocyte count and a serum creatinine of 1.1 mg/dL1.1\text{ mg/dL}.

Which of the following is the most appropriate next step in the management of this patient?

  1. Transthoracic echocardiographyCevap
  2. B
    Initiation of systemic glucocorticoids and nebulized albuterol
  3. C
    Intravenous administration of broad-spectrum antibiotics and blood cultures
  4. D
    Interrogation of the pacemaker to shorten the atrioventricular delay
  5. E
    Contrast-enhanced computed tomography of the chest

Cevap

Transthoracic echocardiography is the most appropriate next step to evaluate for pacemaker lead-induced tricuspid regurgitation.
The correct answer is transthoracic echocardiography. This patient's presentation strongly suggests severe tricuspid regurgitation (TR) secondary to mechanical impingement by a recently placed transvenous pacemaker lead. The physical examination reveals classic signs of severe TR, including a prominent 'v' wave (or fused 'c-v' wave) in the jugular venous pulse, which occurs during ventricular systole as a large regurgitant volume fills the right atrium. Additionally, the patient has a holosystolic murmur at the left lower sternal border that increases with inspiration (Carvallo's sign) and a pulsatile liver, both of which are highly specific for severe TR. Right-sided heart failure causes systemic venous congestion, leading to hepatomegaly, abdominal discomfort, and peripheral edema. Transthoracic echocardiography is the most appropriate next step to confirm the diagnosis, evaluate the severity of TR, and visualize the interaction between the pacemaker lead and the tricuspid valve apparatus.

Adım Adım Çözüm

1
Analyze the patient's physical examination findings and hemodynamics.
The patient has a prominent systolic 'v' wave in the jugular venous pulse, a pulsatile liver, and an inspiratory-increasing holosystolic murmur at the left lower sternal border.
These findings represent the classic, pathognomonic triad for severe tricuspid regurgitation (TR) with subsequent right-sided heart failure and systemic venous congestion.
2
Correlate the suspected diagnosis with the patient's recent medical history.
The patient underwent placement of a dual-chamber transvenous pacemaker 4 weeks ago.
Transvenous pacemaker leads must pass through the tricuspid valve apparatus to reach the right ventricular apex. A recognized mechanical complication is lead impingement on the tricuspid leaflets, preventing proper coaptation and rapidly causing severe TR.
3
Determine the most appropriate initial diagnostic or therapeutic intervention.
Transthoracic echocardiography is required.
Echocardiography is the gold-standard initial non-invasive test to confirm the presence and severity of TR, and to visualize the mechanical interaction between the pacemaker lead and the valve.

Anahtar Kavram

Transvenous pacemaker lead impingement on the tricuspid valve can cause severe tricuspid regurgitation, presenting with acute right heart failure, prominent jugular venous v-waves, and a pulsatile liver. Transthoracic echocardiography is the initial diagnostic test of choice.
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