Article, Cardiology

Focused cardiac ultrasound diagnosis of right-sided endocarditis

Focused cardiac ultrasound diagnosis of “>Case Report

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American Journal of Emergency Medicine

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Focused cardiac ultrasound diagnosis of right-sided endocarditis?,??

Abstract

Endocarditis is a serious infection of the innermost muscle layer of the heart and can lead to significant mortality and morbidity. Echocardiography is instrumental to the Timely diagnosis of this disease entity. We discuss the case of a patient presenting to the emergency department (ED) with fever of unclear etiology. The diagnosis of right-sided endocarditis was made using focused cardiac ultrasound. A 46-year-old man with a history of intravenous drug abuse presented to the ED complaining of fevers and headaches. Focused cardiac ultrasound demonstrated a tricuspid vegetation. The patient was promptly treated for right-sided endocarditis. This case illustrates the use of focused cardiac ultrasound to facilitate the Early diagnosis and management of endocarditis in the ED.

Endocarditis is an infection with serious morbidity and mortality. There are 10,000 to 15,000 new cases in the United States each year [1]. A review of current literature demonstrates few cases of endocarditis diagnosed by focused cardiac ultrasound in the emer- gency department (ED).

A 46-year-old man presented to the ED with a primary complaint of headache. He described diffuse headaches for 5 days that radiated bilaterally down his neck with associated fevers and postural lightheadedness. The patient also admitted to frequent intravenous drug use and skin popping, with the most recent use 3 days before presentation. The patient denied cough, nausea, vomiting, diarrhea, shortness of breath, chest pain, or new skin lesions.

On physical examination, the patient was an alert and oriented male with a blood pressure of 147/85 mm Hg, pulse of 128 beats per minute, respiratory rate of 20 breaths per minute, and an oral temperature of 39.2?C. Extraocular movements were intact. The patient had no meningismus. The cardiac examination demonstrated tachycardia with no murmurs, rubs, or gallops appreciated. Pulmo- nary and Abdominal examinations were unremarkable. Neurological- ly, the patient had normal cranial nerve and cerebellar examinations, symmetric motor strength, and intact sensation. The patient’s extremities demonstrated evidence of chronic scarring to both antecubital fossae without erythema, mass, or fluctuance. The patient had no subungual splinter hemorrhages or painful finger nodes on skin examination of his extremities.

Laboratory analysis was significant for a creatinine of 1.9 mg/dL (0.66-1.25 mg/dL) and a lactate of 1.3 mmol/L (0.7-2.1 mmol/L), with an otherwise normal basic metabolic panel and complete blood count.

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Neither chest radiograph nor a urinalysis confirmed a source for the fever. A non-contrast computed tomography of the head and lumbar puncture were performed to evaluate for meningitis and neither suggested an etiology for the patient’s symptoms.

The patient continued to be tachycardic and became hypotensive with a blood pressure of 85/50 mm Hg despite 2 L of intravenous normal saline. The emergency physician then performed a focused ultrasound of the inferior vena cava and the heart with a Sonosite (Bothell, WA) M-turbo ultrasound system using a P21 x phased array probe. The inferior vena cava showed little variation with the respiratory cycle. The calculated Caval index of less than 50% suggested no significant intravascular volume depletion. Parasternal long and short axis views of the heart were unremarkable for a pericardial effusion, a depressed ejection fraction, or an enlarged right ventricle (Video 1 and 2). On the subxiphoid view, a large vegetation on the Tricuspid valve with thickening of the valve leaflets was appreciated (Video 3).

Based upon this bedside finding, 3 sets of blood cultures were drawn, the patient was started on Intravenous antibiotics, cardiotho- racic surgery was consulted, and the patient was admitted to the intensive care unit. Transthoracic echocardiography performed by the department of cardiology demonstrated a 2 x 1 cm tricuspid vegetation with severe tricuspid insufficiency. The blood cultures grew methicillin-resistant Staphylococcus aureus in all 6 bottles by day

2. The patient’s hospital course was complicated by significant Lower extremity edema that responded to furosemide, and he was discharged after a 6-week course of intravenous vancomycin.

Endocarditis is an infection of the innermost muscle layer of the heart. Risk factors for endocarditis include prosthetic heart valves, structural heart disease, and intravenous drug use. The epidemiology and prognosis of right-sided and left-sided endocarditis are quite different. Right-sided endocarditis affects younger patients, intrave- nous Drug users, and is associated with larger vegetations and fewer complications [2]. One analysis of intravenous drug users with right- sided endocarditis demonstrated a mortality rate of 7% [3]. S aureus was the most common organism identified, and patients with vegetations greater than 2 cm had higher mortality rates as compared with those with vegetations less than 2 cm (33% vs 1.3%).

The Duke criteria for Infective endocarditis are well established for diagnosing endocarditis with one of the major criteria being evidence of an intracardiac vegetation, abscess, or new valvular regurgitation on echocardiogram. Therefore, ultrasound plays an essential role in the diagnosis of this disease entity. The 2 methods of obtaining a cardiac ultrasound for the evaluation for endocarditis are transtho- racic echocardiography (TTE) and transesophageal echocardiography . Studies comparing these 2 modalities in the diagnosis of all types of endocarditis demonstrated sensitivities ranging from 87% to 100% for TEE and 30% to 63% for TTE [4]; however, the sensitivities of

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these modalities were equal when applied to intravenous drug-using patients suspected of having only right-sided endocarditis. In these patients, the only benefit demonstrated by TEE was a more precise characterization of the vegetations [5]. The European Association of Echocardiography recommendations for the practice of echocardiog- raphy in infective endocarditis advise that TEE is not mandatory if the TTE demonstrates a clear focus for infection [6]. Transesophageal echocardiography is only indicated if there is suspected pulmonary valve endocarditis, an implanted cardiac device, moderate to High clinical suspicion of right-sided endocarditis with a nonsuggestive TTE, or poor acoustic TTE windows [5].

Although ultrasound is important in the diagnosis of endocar- ditis, there are only a few published case reports of the diagnosis made in the ED by focused cardiac ultrasound. In these cases, endocarditis was diagnosed using the parasternal cardiac views [7,8]. The right side of the heart and the morphology of the tricuspid valve are not well seen on the parasternal views and are best visualized with the subxiphoid or Apical 4-chamber views. In this case, the subxiphoid view adequately visualized the tricuspid valve vegetation.

Another interesting aspect of this case was the unremarkable cardiac examination. A patient who had severe valvular insufficiency on auscultation would be expected to have an appreciable regurgi- tation murmur upon cardiac auscultation. In this case, neither the emergency physicians nor the intensivist noted the presence of murmur. However, there are limitations to performing a thorough cardiac examination in the ED. The constant activity in the ED creates ambient noise that could limit the sensitivity of cardiac auscultation. Furthermore, one study demonstrated that the sensitivity of auscul- tation of tricuspid regurgitation ranged from 12% to 33% when performed by internal medicine residents and cardiology fellows [9]. Chronic obstructive pulmonary disease, obesity, and the training level of the examiner were all associated with false-negative cardiac auscultation examinations.

This case illustrates the use of focused cardiac ultrasound to facilitate the early diagnosis and management of right sided endocarditis in the ED. Focused cardiac ultrasound enabled the emergency physician to promptly initiate treatment and deter- mine appropriate disposition for a patient who presented with this etiology.

Supplementary materials related to this article can be found online at http://dx.doi.org/10.1016/j.ajem.2013.2.003.

Neil J. Pathak MD Department of Emergency Medicine Emergency Ultrasound Division

St Luke’s/Roosevelt Hospital Center New York, NY 10019, USA

E-mail address: [email protected]

Lorraine Ng MD Division of Pediatric Emergency Medicine and Division of Emergency Ultrasound

Columbia University College of Physicians and Surgeons

New York-Presbyterian Morgan Stanley Children’s Hospital New York, NY 10032, USA

Turandot Saul MD, RDMS Resa E. Lewiss MD, RDMS Department of Emergency Medicine Emergency Ultrasound Division

St Luke’s/Roosevelt Hospital Center New York, NY 10019, USA

http://dx.doi.org/10.1016/j.ajem.2013.02.003

References

  1. Bayer AS. Infective Endocarditis. Clin Infect Dis 1993;17(3):313-20.
  2. San Roman JA, Lopez J, Vilocosta I, Lopez J, Revilla A, Arnold R, et al. Role of transthoracic and transesophageal echocardiography in right-sided endocarditis: one echocardio- graphic modality does not fit all. J Am Soc Echocardiogr 2012;25:807-14.
  3. Hecht SR, Berger M. Right-sided endocarditis in intravenous drug users. Prognostic features in 102 episodes. Ann Intern Med 1992;117:560-6.
  4. Jacob S, Tong A. Role of echocardiography in the diagnosis and management of infective endocarditis. Curr Opin Cardiol 2002;17:478-85.
  5. San Roman JA, Vilocosta I, Zamorano JL, Almeria C, Sanchez-Harguindey L. Transesophageal echocardiography in right-sided endocarditis. J Am Coll Cardiol 1993;21:1226-30.
  6. Habib G, Badano L, Tribouilloy C, Vilacosta I, Zamorano JL, Galderisi M. European Association of Echocardiography. Recommendations for the practice of echocardi- ography in infective endocarditis. Eur J Echocardiogr 2010;11:202-19.
  7. Cheng A, Levine D, Tsung J, Phoon C. Emergency physician diagnosis of pediatric infective endocarditis by point-of-care echocardiography. Am J Emerg Med 2012;30:386.e1-3.
  8. Walsh B, Bomann J, Moore C. Diagnosing infective endocarditis by emergency department echocardiogram. Acad Emerg Med 2009;16:572-3.
  9. Kinney E. Causes of false-negative auscultation of regurgitant lesions: a Doppler echocardiographic study of 294 patients. J Gen Intern Med 1988;3:429-34.

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