< Presentation of Case >
A 58-year-old woman presented to the hospital with increasing episodes of chest tightness and palpitations over the period of 6 months before this evaluation.
She had been in her usual state of health until October 2012, when an episode of transient chest tightness developed. Between October and December 2012, she experienced another two episodes of chest tightness after meals. The symptoms occurred in the sitting position. The discomfort was located at the substernal area, with no radiation, and lasted only a few minutes. There was no prodrome. She reported no dizziness, diaphoresis, near-syncope, or severe chest pain. The discomfort subsided spontaneously. She did not see a doctor, because the symptoms were short-lived.
She had been otherwise well until she was struck by severe chest tightness, dizziness, and vomiting triggered by food odors during a meal on 2013/01/09. She sought medical attention at the emergency room (ER) of the National Taiwan University Hospital Hsinchu Branch immediately. The chest pain was the most severe in her experience and she rated it as 8 on a pain scale of 1 to 10 with 10 indicating the most severe pain. At ER, she could not provide the details of the pain pattern because the pain was so severe that she mourned and twisted in the bed at ER. She put her fist on the anterior chest wall while the ER physician performed a focused survey. An immediate bedside electrocardiography (ECG) showed sinus rhythm, with ST elevation in leads I and aVL (figure 1). She appeared distressed, with cold clammy skin. A focused exam found that the temperature was 36.2℃, the heart rate 78 beats per minute, the blood pressure 134/80 mmHg, the respiratory rate 20 breaths per minute, and SpO2 98% while she was breathing ambient air. The jugular veins were not engorged and the lungs were clear on auscultation. There was no pitting edema.
Because of the acute chest pain and ST elevation >1 mm on two consecutive leads of ECG, an emergent coronary angiography that was performed 25 minutes after her arrival at ER revealed patent coronary arteries, with no evidence of coronary spasm or embolism. No myocardial bridge was identified. Ventriculography of the left ventricle (LV) showed global hypokinetic LV, and subtle regional-wall motion abnormality at the anterior wall. Aspirin was begun. During the stay in the intensive care unit (ICU) for 36 hours, no episode of paroxysmal atrial fibrillation or ventricular arrhythmias were noted. The heart rate and blood pressures were in the normal ranges. Before discharge, the initial findings of regional-wall motion abnormality fully recovered with good LV contractility (LVEF, 73%) by echocardiography. She was discharged on 2013/01/12. The ST elevations on ECG resolved (figure 2). The acute ST elevation event was attributed to possible coronary vasospasm.
Between 9 January, 2013 and 2 May, 2013, she received regular follow-up at the outpatient clinic. The home blood-pressure monitor program failed because she did not note any high blood pressure reading in the first week. The home blood pressures were within 110-120/70-75 mmHg. She resumed her usual daily life, with good exercise tolerance. She cycled for her daily grocery shopping. She walked and climbed stairs without effort angina. There was no recurrent chest discomfort until 4 months later (2013/05/02).
On 2013/05/02, she had a sudden onset of chest tightness, headache, and diaphoresis while sitting in a chair. The above symptoms peaked in intensity over a few minutes, which lasted one hour and subsided spontaneously. The chest tightness was just like the previous episode, and the headache was new. The headache, as she recalled, was located diffusely over the whole cranium. No pulsatile characteristics could be recalled. The chest tightness developed again in a more severe form, which lasted longer, and she was brought to the ER of NTUH Hsin-Chu Branch again. At the ER, the systolic blood pressure was 220 mmHg. A focused exam disclosed a low-grade fever (37.8℃), bi-basilar crackles of the lungs, and no pedal edema. The white-cell count was 17670 cells/μL. A chest radiograph showed bilateral pulmonary infiltrates. Nitrate infusion, furosemide, and ampicillin/sulbactam were administered by vein. The first ECG showed sinus tachycardia without obvious ST-T changes. On a second ECG follow-up, a non-sustained wide-complex tachycardia was recorded (figure 3). She remained conscious and had palpable pulses while the wide-complex tachycardia was recorded. Amiodarone infusion was begun. A cardiologist was contacted immediately, who performed a second survey at ER. She remained alert and conscious, with partially improved chest discomfort, but appeared agitated in a sitting position. No prodrome was identified this time, either. She reported no fever, nausea/vomiting, diarrhea, abdominal pain, or any emotional stress. Both the patient and her family members denied a history of hypertension when questioned by the ER physician.
She was married and lived with family. She denied use of alcohol, cigarette, or betel nut. She had had no history of hospitalization until January 2013. There was no family history of hypertension, diabetes mellitus, coronary artery disease, or heart failure.
A diagnosis of recurrent acute heart failure without obvious cause was made. She was admitted to the medical intensive care unit. However, progressive hypotension and respiratory distress were noted soon after admission while she reported that the chest discomfort disappeared. The heart rate was 110 bpm, blood pressure 90/60 mmHg, respiratory rate 30/min, with SpO2 92% while she was breathing oxygen at a flow rate of 5 L/min with the use of a simple oxygen mask. Bilateral crackles were heard all over the lungs. Within 20 minutes, after the nursing staff performed weight measurement in the ICU, she appeared diaphoretic with altered mental status. The blood pressure dropped to 80/40 mmHg. She was then intubated and dopamine infusion was begun. Echocardiography showed normal sizes of the four chambers and global hypokinesia, with severely impaired LV contractility (LVEF 31%). Regional wall-motion abnormality was identified with hypokinesia at the apex. After she awakened, the blood pressure recovered to 110 mmHg. Pink-frothy sputum was noted in the endotracheal tube, which necessitated continuous suction.100 ml of pink-frothy fluid were drained from the airway within 1 hour. She was sedated with midazolam infusion and fentanyl infusion was also started. The physical examination before sedation confirmed clear consciousness. The conjunctivae were pink and the sclerae anicteric. The jugular veins were engorged to the mandibular angles. No goiter was found. She was orally intubated with mechanical ventilator support. There were diffuse bilateral crackles on auscultation. The cardiac examination revealed rapid tachycardia, without murmurs. No LV heave was found. The abdomen, the extremities, the skin, and the back were unremarkable. A diagnostic procedure was performed.
< Laboratory data >
2013/05/02
Hb
(g/dl) |
MCV
(fL) |
Plt
(k/uL) |
WBC
(/uL) |
Seg
(%) |
Eos.
(%) |
Mono.
(%) |
Lym.
(%) |
15.8 |
89.0 |
378 |
17670 |
85.0 |
0.1 |
1.5 |
13.1 |
ALT
(U/L) |
Cr
(mg/dl) |
Na
(mmol/L) |
K
(mmol/L) |
Ca
(mmol/L) |
Glucose
(mg/dl) |
CK-MB
(U/L) |
Troponin I
(ng/ml) |
91 |
1.2 |
140 |
3.3 |
2.54 |
262 |
19.7 |
0.03 |
After reviewing the history, the following were confirmed: stress-induced cardiomyopathy (recurred in separate episodes), with full recovery of LV dysfunction after the first attack, non-sustained ventricular tachycardia, and patent coronary arteries. In searching for the cause of recurrent LV dysfunction, a focused search for secondary hypertension was attempted at ICU. There was no blood pressure discrepancy between the two arms. A right adrenal tumor was noticed by sonography (figure 4). Computed tomography with administration of contrast material showed a 3.8x3.4x3.3-cm right adrenal tumor (figure 5). 24-urine catecholamines and VMA (vanillylmandelic acid) were checked. She was referred to the NTUH, Taipei, on 2013/05/03. The cardiac enzymes peaked on 2013/05/03 (CK 885 U/L, CK-MB 63 U/L, and troponin I 13.8 ng/ml). The 24-hour urine VMA result was 9.3 mg (24 hour urine, reference range: 1-7 mg). Doxazosin was begun on 2013/05/06 when a diagnosis of pheochromocytoma was made. Extubation was done smoothly on 2013/05/07. She was transferred to the general ward on 2013/05/09.
At the general ward, doxazosin was continued. She had no recurrent episodes of chest tightness, headache, or diaphoresis. Her systolic BP was around 100-110 mmHg. An urologist was consulted and laparoscopic adrenalectomy was performed on 2013/07/03. The pathology confirmed the diagnosis of pheochromocytoma. Follow-up 24-hour urine VMA was lowered to 2.3 mg. She now lived a normal life. She bicycled as usual and was free of palpitations, chest discomfort, and hypertension 6 months after the surgery.
< 病例討論 >
本案例最後診斷為嗜鉻細胞瘤(pheochromocytoma)所引起之反覆發作的急性心衰竭。其特別之處在於，病患平時沒有高血壓，她在第二次就醫時才被量到過一次高血壓，之後的血壓都在正常至偏低的範圍內。她在兩次急性腎上腺素大量分泌時，都有特殊的心臟表現：第一次是以急性胸痛併ST節段上升，並直接接受了緊急心導管檢查。第二次則合併心室頻脈 (ventricular tachycardia)及嚴重的收縮期心衰竭。
嗜鉻細胞瘤的表現大部份以高血壓 (sustained hypertension)為主。嗜鉻細胞瘤的發生率在2-8/10萬人/年之間。 約佔所有高血壓的診斷的0.1%。嗜鉻細胞瘤中，偶有陣發性高血壓 (paroxysmal hypertension)的，甚至以低血壓 (orthostatic hypotension)表現的特殊情況，這與大量腎上腺素分泌時，身體水份容積狀態(volume status), 及分泌的腎上腺素(epinephrine)和正腎上腺素(norepinephrine)比例有關。 嗜鉻細胞瘤的典型症狀，為triad of headaches, sweating attacks, and palpitation/ tachycardia (三合症狀：包含頭痛，盜汗，與心悸/心跳過速) 。但是實際上，甚少病患以此三合一之典型表現。嗜鉻細胞瘤在新的治療技術發展下，以及新的檢查評估流程下，開始漸漸以不同的相貌出現在我們的臨床照護中。早在1976就有文獻報告，嗜鉻細胞瘤合併急性ST節段的變化，跟急性缺血性心臟病是幾乎無法區分的。1 嗜鉻細胞瘤被報告過，可以引起心電圖的缺血性變化， 有：hyper-acute T wave, T wave inversion, ST elevation, ST depression等等。在今日心臟科與急診科高度發展緊急心導管業務之下，開始有嗜鉻細胞瘤是以急性胸痛或胸悶，併ST節段上升表現，而被當作是STEMI (ST節段上升之心肌梗塞)，使得病人因此接受緊急心導管檢查。而這些病患的冠狀動脈都是通暢無狹窄的。在2000開始有研究人員統計，在25例病理確診的嗜鉻細胞瘤中，有5位病患是以急性冠心症表現，在接受嗜鉻細胞瘤手術切除前，接受了心導管針對冠狀動脈的檢查(佔該報告中病人總數的20%)。2
嗜鉻細胞瘤在心血管系統的表現可以包含：高血壓，盜汗，心悸，胸痛，腹痛，暈厥 (syncope), 喘，肢端發白 (pallor)，急性心肌梗塞的心電圖變化，急性心衰竭，心室頻脈等。3-5嗜鉻細胞瘤可以引發急性兒茶酚胺致使的心肌病變 (acute catecholamine cardiomyopathy, ACC). 反覆發作的心臟衰竭，併左心室收縮功能下降，及心室頻脈，都是ACC的表現之一。這些變化，文獻上曾報告過在切除嗜鉻細胞瘤後，可以逆轉心衰竭的變化。6
本案例在第二次加護病房住院時，綜觀其特殊之處：1. 曾ST節段上升併胸痛，心導管檢查呈現冠狀動脈無狹窄，2. 曾急性心衰竭發作，但是之後左心室收縮功率及局部運動障礙又完全恢復至正常，3. 在急診曾短暫心室頻脈，但是最近一次的心臟超音波又無見到結構上心臟有異常，在加護病房住院之初即直接懷疑有嗜鉻細胞瘤。而在加護病房時即在做心臟超音波時一併檢查雙側腎上腺。之後再以生化檢查確診。
此一案例突顯出，在心電圖呈現缺血性及心肌酵素異常時，儘管心導管檢查顯示血管正常，還是要仔細分析可能的原因，並根據疾病生理學作有系統的檢驗，才能夠得到正確診斷。
< References >
- Cheng TO, Bashour TT: Striking electrocardiographic changes associated with pheochromocytoma. Masquerading as ischemic heart disease. Chest, 70: 397-399, 1976
- Liao WB, Liu CF, Chiang CW, Kung CT, Lee CW: Cardiovascular manifestations of pheochromocytoma. Am J Emerg Med, 18: 622-625, 2000
- Sheikhzadeh A, Fatourechi V, Paydar D, Nazarian I: Unusual cardiovascular manifestations in a case of pheochromocytoma. Clin Cardiol, 6: 136-142, 1983
- Subramanyam S, Kreisberg RA: Pheochromocytoma: a cause of ST-segment elevation myocardial infarction, transient left ventricular dysfunction, and takotsubo cardiomyopathy. Endocrine practice : official journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists, 18: e77-80, 2012
- Musuraca G, Imperadore F, Terraneo C, Vaccarini C, Prati D, Centonze M, Vergara G: Pheochromocytoma mimicking a non-ST elevation acute myocardial infarction. Cardiology journal, 16: 355-357, 2009
- Giavarini A, Chedid A, Bobrie G, Plouin PF, Hagege A, Amar L: Acute catecholamine cardiomyopathy in patients with phaeochromocytoma or functional paraganglioma. Heart, 99: 1438-1444, 2013
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Case Discussion
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