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A 55 year-old man suffered from chest tightness,
dyspnea, and palpitation in recent days.
Brief History
This patient had been well until
this June, when he suffered from general malaise, chest
discomfort, and shortness of breath for one month. Body weight
loss with ten kgs in one month was also noted. He had a health
check-up at a clinic where iron deficiency anemia was told
(Hb: 2.9 g/d, MCV: 67.1 fL, Ferritin: 4.38 ng/mL). He then
visited a university OPD for help on August 14. Besides, a S3
gallop and lower leg edema were found, which were
later proved due to high output heart failure by cardiac echo.
His symptoms improved after component therapy and
iron supplementation. However, orthopnea, exertional dyspnea, chest
tightness, and persistent palpitation developed since late October. He
visited ER on November 3.
On reviewing his past history, he
denied any systemic diseases. He has no history of allergy. He
underwent cholecystectomy in 1990 and partial gastroectomy due
to upper gastrointestinal bleeding in 1966.
On examination, the
blood pressure was 140/80 mmHg and irregular pulse rate with 140 beats
per minute. The body temperature was 37.9℃ and respiratory rate
26 per minute. The conjunctiva was mild pale and the
sclera was anicteric. There were no neck lymphadenopathy
or goiter palpable. The jugular vein was engorged.
Chest auscultation showed fine crackles over bilateral lung fields.
The heart sound was grade II/VI systolic murmur noted at
left lower sternal border. The abdomen was soft and bowel
sound was hypoactive. Bilateral lower limb edema was found.
The work-up at ER included: ECG (Figure 1) showed atrial fibrillation
(Af) with rapid ventricular rate and inverted T on leadV5~V6, II,
III, and aVF and CXR (Figure 2) disclosed cardiomegaly with
bilateral pleural effusion with atelectasis of RML and RLL.
Laboratory Data
1. CBC/DC
|
|
WBC
(K/μL) |
RBC
(M/μL) |
HB
(g/dL) |
MCV
(fL) |
PLT
(K/μL) |
Seg
(%) |
Lym
(%) |
Eos
(%) |
|
11/3 |
8.42 |
3.55 |
8.6 |
76.9 |
298 |
75.2 |
3.5 |
0.1 |
|
11/7 |
16.41 |
4.22 |
10.6 |
76.5 |
297 |
89.4 |
4.7 |
1.6 |
2. ABG
|
|
pH |
PaCO2
(mmHg) |
PaO2
(mmHg) |
HCO3-
(mEq/L) |
B.E
(mEq/L)
|
FiO2 |
Ventilator
Mode |
|
11/3 |
7.42 |
31.5 |
77.0 |
19.8 |
-3.7 |
0.3 |
nasal cannula 3 L/min
|
3. BCS
|
|
BUN
(mg/dL)
|
Cre
(mg/dL)
|
CK
(U/L) |
CK-MB
(U/L)
|
Troponin I
(ng/mL) |
Na
(mmole/L)
|
K
(mmole/L)
|
|
11/3 |
27 |
0.7 |
336 |
39 |
0.428 |
136 |
3.8 |
|
11/4 |
|
3.1 |
133 |
17 |
|
|
|
|
|
T/D Bil
(mg/dL)
|
AST
(U/L) |
ALT
(U/L) |
rGT
(U/L) |
ALP
(U/L)
|
|
11/3 |
3.4/2.3 |
245 |
198 |
|
|
|
11/4 |
5.5/3.1 |
636 |
575 |
33 |
240 |
4. Iron profile
|
|
Iron (μg/dL)
Range: 50 ~ 150 |
TIBC (μg/dL)
Range: 250 ~ 370 |
Ferritin (μg/L)
Range for woman:
10 ~
200 |
|
11/5 |
11 |
303 |
280 |
5. Thyroid function
|
|
hsTSH (μIU/mL)
Range: 0.400 ~ 4.000 |
Free T4 (ng/dL)
Range: 0.80 ~ 1.90 |
|
11/4 |
0.003 |
3.49 |
6. Viral markers
|
|
Anti-hepatitis C |
HBsAg (EIA) |
IgM-Anti-HAV |
|
11/6 |
negative |
negative |
Negative |
Clincial course & treatment
Under
the impression of Af with rapid
ventricular response, decompensated congestive heart failure
(CHF) and suspceted non-Q myocardial infarcction, he
was admitted to MICU. Orthopnea improved after prescribed with diuretics,
captopril and intravenous digoxin. Pleural effusion was
drained with the characters of transudate. Echocardiography
showed preserved LV contractility with enlarged
LA and LV and no significant valvular abnormality was found.
The tachycardia persisted despite the usage of intravenous
digoxin, and daily dosage of 50 mg of carvedilol. Amiodarone
(900mg per day) was prescribed and heart rate decreased
to 80 beats per minute gradually after 1 days' treatment.
Due to no obvious CAD risk factors and unknown etiology
of atrial fibrillation, thyroid function was checked with
the results compatible with hyperthyroidism. Amiodarone was
substituted by sotalol (160mg twice daily) and carbimazole (10
mg three times a day) was also given. By the way, abnormal liver
function was noted without the evidence of viral origins,
which was attributed to liver congestion. Unfortunately,
Torsade de pointes occurred with loss of consciousness
on November 5. The condition was improved after cardioversion
and supply with magnesium . Sotalol was replaced by
continuous intravenous infusion of esmolol. An episode of
spiking fever (39°C) happened on November 7. Thyroid storm was
highly suspected; the medications were shifted to diluted
Lugol's solution (10 mL t.i.d), Rinderon (4mg qd), propranolol
(40mg q.i.d), and propylthiouracil (100 mg q8h). Not only did
the fever and tachycardia ameliorate half a day later but the
patient's consciousness recovered also. Extubation was done
smoothly and he was transferred to general ward on November 9.
He was discharged with stable conditions on November 18. The
follow-up CXR also disclosed resolution of heart
size.
 案例分析
本案例的病程必須分成三個部份來看；
第一部份：缺鐵性貧血所造成的高心搏量型心衰竭。如本案例所述，病人仍然會有心臟衰竭的表徵(容易疲倦、胸口不適、及運動耐受性不足)，甚至ｘ光片也有心臟擴大，肋膜積水。這些表現與一般的心收縮力不足之心臟衰竭很難區分；很重要的一點在理學檢查上可觀察到病人有非常嚴重的貧血(
通常Hb< 5.0 /dL). 此時對於病人的處置，就必須加上輸血治療，並且找出貧血的原因，才能根治。
第二部份：病人於住院前開始有心臟衰竭的徵狀，這時候要作一些鑑別診斷。由心臟衰竭的原因開始著手，可分成幾點(1)心搏出量減少者(low
output)，包含有(a.)收縮性(systolic dysfunction)如 late hypertension,
diabetic, toxic, valvular,(b.)舒張性(diastolic dysfunction)如
ischemic, early hypertension, aortic stenosis, hypertrophic
obstructive cardiacmyopathy (2)心搏出量增加者(high output)，如sepsis,
anemia, thyrotoxicosis, arteriovenous fistula。
本案例病人由臨床症狀來看並不是很容易區分原因，但是由住院後之檢查來看，心臟衰竭的症狀在治療之後有改善，但是Atrial
fibrillation with rapid ventricular
response，雖經使用Digoxin仍無法緩解，其原因無法用瓣膜性或用肺部問題解釋，因此對於不明原因新近發生的
Atrial
fibrillation，我們應予測量甲狀腺功能，病人最後證實是甲狀腺功能亢進，經給予治療而使心跳得以控制。本案例病人臨床上的表現，並沒有典型甲狀腺功能亢進者所該有的，這在中老年人有部分病人可能會如此，也有人會以心臟衰竭或atrial
fibrillation 表現，甚至有些老人會表現倦怠，食慾不振等，這是必須注意的。
第三部份：病人證實是Hyperthyroidism之後，我們一方面使用Antithyroid
drug，一方面為了避免干擾甲狀腺功能而停用Amiodarone，以sotalol取代，而病人住院後三天，即Amiodraone
使用一天之後，產生thyrotoxicosis 之症狀，經給予steroid,
s-blocker及propylthiouracil 之後，獲得緩解。此病人發生thyrotoxicosis
之原因是否與Amiodarone
有關較難確定。文獻上報告通常必須要累積到相當劑量之後才有可能發生。甲狀腺功能異常，統計約2.1%-12.1%的人會發生甲狀腺功能亢進。若病人已知有甲狀腺功能異常，則應該要儘量避免使用Amiodarone以免干擾甲狀腺功能，惡化已存在的症狀。
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Case Discussion