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A chest radiograph of a 38-year-old woman, who was diagnosed with rheumatic mitral stenosis, revealed cardiac enlargement due to a giant left atrium that was distorting the cardiac structures. The patient's cardiothoracic ratio was approximately 0.90.
A giant left atrium can readily be delineated by echocardiography. Optimal timing of surgery is important in cases of mitral stenosis, because delaying mitral valve replacement can lead to fatal outcomes.
To our knowledge, the left atrial diameter of 18.7 cm that we found in our patient is the largest reported to date.
The left atrium dilates and hypertrophies in patients with rheumatic mitral stenosis. Occasionally, the left atrium reaches extreme sizes. In these cases, mitral stenosis may present alone or with mitral insufficiency, or it may present as mixed mitral disease, with predominant rheumatic mitral stenosis. Transthoracic echocardiography is the easiest and least expensive method for diagnosing and monitoring the disease. Intraoperative transesophageal echocardiography helps the surgical team evaluate the effectiveness of artificial valves.
In April 2004, a 38-year-old woman was admitted to our institution with dyspnea and palpitations. These symptoms had been present for 4 years, but they had worsened during the last 15 days. She had been diagnosed with rheumatic heart disease 4 years earlier by echocardiography, which had revealed a mitral valve area of 0.5 cm2 and a left atrial diameter of 10 cm. She had refused surgery when it was suggested at that time. Since then, she had been receiving medical treatment.
Physical Examination. The physical examination revealed that the patient's blood pressure was 80/40 mmHg, her heart rate was 110/min with atrial fibrillation, her neck veins were distended, and crepitations were present at the basal regions of her lungs. A diastolic murmur and a 3+ to 4+ pansystolic murmur were present at the midclavicular line, and there was 2+ peripheral edema.
Transthoracic echocardiography showed a mitral valve area of 0.3 cm2, 3+ mitral insufficiency, and 3+ to 4+ tricuspid insufficiency. The patient's left atrial diameter was 18.7 cm. Electrocardiography indicated atrial fibrillation and right ventricular enlargement. A chest radiograph revealed massive cardiomegaly and pleural fluid in both sides of the thorax (Fig. 1). Transthoracic echocardiography demonstrated a left atrial diameter of 18.7 cm and a mitral valvular area of 0.3 cm2. The maximal gradient was 30 mmHg, and the left ventricular ejection fraction was 0.40 (Fig. 2).
The patient was judged to be in New York Heart Association functional class IV. We tried to stabilize her and to manage the advanced heart failure with infusions of furosemide (30 mg/hour) and isosorbide dinitrate (5 μg/min), but her dyspnea continued after 7 days of treatment. Upon obtaining the necessary consent from the patient and her family, we decided to perform surgery.
Operation and Intensive Care. The patient underwent surgery in this clinical status and could be intubated only in an almost-sitting position. A Swan-Ganz catheter was placed. The central venous pressure was 18 mmHg, the pulmonary artery pressure was 65/35 mmHg, and the systemic blood pressure was 80/50 mmHg. The pulmonary capillary wedge pressure could not be measured. With the patient under general anesthesia, we opened the mediastinum via a midsternal incision, opened the pericardium, and instituted cardiopulmonary bypass by cannulating the superior vena cava, inferior vena cava, and aorta. An aortic cross-clamp was placed. Cardiac arrest was attained by 33 °C systemic hypothermia and antegrade administration of cold-blood cardioplegic solution.
After performing a right atriotomy, we observed severe insufficiency of the tricuspid valve. We entered the left atrium through the atrial septum and found advanced fibrocalcification of the mitral valve. We resected the mitral valve with preservation of the posterior mitral leaflet, and we placed a 31-mm St. Jude mechanical valve (St. Jude Medical, Inc.; St. Paul, Minn). An organized thrombus of 1 to 2 cm in diameter, which adhered to the left atrial wall, was removed; a 5-cm left atrial plication was performed; and the left atrial appendix was ligated internally with 5–0 polypropylene suture material. A De Vega tricuspid valve annuloplasty was performed with a 33-mm sizer. The cross-clamp time was 62 min; the cardiopulmonary bypass time was 105 min.
The patient was transferred to the postoperative intensive care unit. The drainage tubes were removed on the 1st postoperative day, and she was extubated on the same day. However, she had to be reintubated on the 2nd postoperative day because of dyspnea. A tracheostomy was performed on the 5th day. She had hypotension and bradycardia on the 10th day, when, after failing to respond to cardiopulmonary resuscitation, she died.
Delaying an operation for mitral valve replacement can lead to fatal outcomes. When surgery is delayed, increased pulmonary artery pressure contributes to an increase in right-side pressures and unfavorably affects mortality and morbidity rates. Therefore, optimal timing is crucial for reducing mortality rates during mitral valve operations.
Sinatra and colleagues1 reported the case of a 56-year-old man with a left atrial diameter of 17 cm as measured by echocardiography. Magnetic resonance imaging revealed a left atrial size of 18 × 20 × 17 cm in that patient. (Due to the clinical status of our patient, we could not perform magnetic resonance imaging.) The left atrial diameter of 17 cm reported by Sinatra's group was the largest diameter that we could find in the literature.
Hurst2 states that, in cases of giant left atrium, mitral regurgitation is more profound than mitral stenosis, atrial fibrillation is almost always present, chest radiography may reveal pleural fluid, and dysphagia may be present. Our patient could not cooperate well, so we obtained her history from relatives, who stated that she had experienced dysphagia. In these cases, pulmonary edema and dyspnea are always observed due to increased pulmonary pressure. In the United States, similar cases were reported until the late 1940s; today, though, giant left atrium cases are not frequently reported in the United States, and most of these involve immigrants.2
According to the definition by Isomura and coworkers, left atria larger than 6 cm in diameter are giant left atria.3 Because rheumatic heart disease is common in Turkey and we regularly encounter enlarged left atria, we suggest that left atria with a diameter of more than 10 cm should be regarded as giant, and that a diameter of 6 to 10 cm should be considered large.
Johnson and associates4 have proposed that left atrial enlargement is not solely due to mitral regurgitation; it is also affected by the quality of the left atrial wall. Lessana and co-authors5 described partial autotransplantation to reduce the size of the left atrium. In this technique, after cross-clamping, the superior vena cava, aorta, and pulmonary artery are detached, and the heart is easily moved upward. The standard now is to resect the left atrium until its diameter decreases to 5 cm. Mitral valve replacement is performed in this position, and the pulmonary artery, aorta, and superior vena cava are reattached. In the case of our patient, left atrial plication decreased the preoperative left atrial diameter of 18.7 cm to 13.3 cm postoperatively.
Because our patient was in a terminal stage with rheumatic mitral stenosis more profound than rheumatic mitral insufficiency, and because of her advanced pulmonary hypertension and other emergent conditions, her risk of death was high. Despite the fatal outcome, we wish to report our findings of an 18.7-cm-diameter left atrium—the largest left atrium reported to date.
Address for reprints: Mehmet Ates, MD, Merdivenkoy Mah. Sairarsi Cad. Emincinarpasa Sok. No: 6 Dicle Apt. D: 24, Goztepe - Kadikoy, 34732 Istanbul, Turkey E-mail: moc.oohay@setamrd