The patient's condition before admission

A 43-year-old Chinese woman of Han ethnicity was transferred to our hospital because of chest tightness and pain in the precordial region at 16:00 Hrs on April 27, 2022, one hour after she received her third booster dose of the COVID-19 vaccine (Beijing KeXing ZhongWei, lot number: 202201004J) at a Community Health Service Center in Hunan Province, China. The pain was described as suffocating and crushing, and was associated with sweating and cold limbs, which appeared 40 min after vaccination (15:40 Hrs).

About 30 min before admission (30 min after vaccination, 15:30 Hrs), she developed generalized itch, accompanied by shortness of breath, nausea, and severe vomiting (watery vomitus consisting of coffee-colored gastric contents). Her vitals were: temperature 36.2℃; pulse rate 110 times/min; respiratory rate 26/min; blood pressure 89/50 mmHg. She was administered oxygen inhalation and anti-allergy treatment (intramuscular promethazine hydrochloride 25 mg; intravenous drip of dexamethasone 10 mg dissolved in 50 mL of normal saline). No vasopressor drugs were administered.​

The patient had no history of smoking or alcohol abuse, diabetes mellitus, or hypercholesterolemia.​ Her obstetric history included 4 pregnancies (1 live birth and 3 abortions). She had a history of developing skin rash after beer consumption, and a history of sudden-onset tinnitus after tetanus vaccination more than 10 years ago. ​Fifteen years ago, she was diagnosed with hepatitis B but was not found to have liver cirrhosis. Her previous medication history was unknown. On examination, her liver and spleen were not palpable, and laboratory tests showed normal liver function.​ There was no personal or family history of coronary artery disease.

The patient's condition in the emergency department

Ten minites after admission (16:10 Hrs), the patient was found to be unconscious and was not responding to calls. She was pale, with cold skin and weak aortic pulsations. Her vitals were: temperature 36.0°C; pulse rate 115 times/min; respiratory rate 24 per min; and blood pressure 75/50 mmHg. An intramuscular injection of epinephrine (0.5 mg) was administered immediately along with intravenous infusion of Ringer's lactate solution. At 16:23 Hrs, her consciousness was restored, and her blood pressure increased to 85/52 mmHg. Electrocardiogram (ECG) showed sinus rhythm, ST-segment elevation in leads I, II, and avL, and ST-segment depression and T-wave inversion in leads III and V1-V4 (Fig. 1). At 16:44 Hrs, her serum cardiac troponin I (cTnI) level was 0.12 ng/mL (normal range, 0–0.028 ng/mL) and creatine kinase-MB (CK-MB) was 16.37 ng/mL (normal range, 0–25U/L). D-dimer, procalcitonin, interleukin-6, and C-reactive protein (CRP) levels were normal. COVID-19 nucleic acid test (throat swab) was negative. Bedside cardiac ultrasound revealed left atrial enlargement and left ventricular global systolic dysfunction with left ventricular ejection fraction (LVEF) of 29.1%. Echocardiography showed wall motion abnormalities namely a segmental hypokinesia in the lateral wall of left ventricle in the apical four-chamber view, consistent with ECG finding, suggesting the presence of anterior descending diagonal branch lesion. Chest auscultation revealed no wheezing; her heart sounds were weak and the possibility of heart failure was considered. The patient was administered dobutamine hydrochloride (15 µg/kg/min) via intravenous pump to maintain blood pressure along with moderate rehydration therapy. Repeated ECG performed at 17:19 Hrs displayed sinus rhythm and a decrease in the extent of ST-segment elevation in leads I, II, and avL compared with the previous ECG (Fig. 2). Compared to the previous ECG, the ST-T change indicated improved heart perfusion. Her blood pressure at 17:30 Hrs was 86/60 mmHg and a repeated intramuscular injection of 0.5 mg of epinephrine was administered. At 17:40 Hrs, her blood pressure had increased to 96/65 mmHg and she showed improved consciousness. She complained of intermittent chest tightness and breathlessness along with intermittent vomiting; she had a generalized punctate red-colored rash. Besides, her B-type natriuretic peptide (BNP) level was elevated (624.70 pg/mL; normal range, < 100 ng/mL), and her cTnI level was 0.16 ng/mL. Her myocardial enzyme spectrum was positive, and she was transferred to the intensive care unit (ICU) of our hospital.

Fig. 1

Emergency electrocardiogram of the patient performed on April 27, 2022 (sinus rhythm, both ST- elevation in leads I, II, and avL, and ST-segment depression and T-wave inversion in leads III and V1-V4)

Fig. 2

Repeated ECG performed on April 27, 2022 (sinus rhythm, ST-segment elevation in leads I, II, and avL has decreased compared to pre-treatment ECG. ​Compared to the previous ECG, the ST-T change indicates improved heart perfusion​)

The patient's status in the ICU

Her physical parameters at admission to ICU were: body weight 60 kg; temperature 36.6°C, pulse rate 69 beats/min; respiratory rate 24 breaths/min; and blood pressure 90/58 mmHg maintained by intravenous administration of dopamine hydrochloride (15 µg/kg/min). On physical examination, she was drowsy and poorly cooperating. There were no signs of jaundice; scattered punctate red skin rashes were observed over the whole body, but there was no bleeding or petechiae. The pupils were bilaterally equal and round, with a dull light reflex. The mouth and lips were cyanotic. Chest auscultation showed bilateral coarse respiratory sounds with scattered wet rales without croup. The heart sounds were weak and rhythmic with no pathological cardiac murmur or pericardial friction sound.

After admission to ICU, the relevant tests were completed, including ECG (Figs. 1, 2 and 3). Her serum primary cTnI was 0.12 ng/mL, the secondary was 0.16 ng/mL, and the tertiary was 2.02 ng/mL; mixed allergen panel indicated total immunoglobulin E (IgE)+, household dust mite ++, and beef + (Table 1). Lung computed tomography (CT) performed on April 28, 2022 showed signs of interstitial pulmonary edema (Fig. 4), which was significantly resolved on May 13, 2022 (Fig. 4). Bedside cardiac ultrasound performed on April 28, 2022 showed left atrium 35 mm, left ventricle 55 mm, low left heart systolic function [left ventricular ejection fraction (LVEF) 29.1%; fractional shortening (FS) 13.6%, mild mitral and tricuspid regurgitation] (Fig. 5). On May 16, 2022, she showed normal heart size and structure, as well as normal cardiac function (LVEF, 70%; FS, 39%). Of note, immediate percutaneous coronary intervention (PCI) was not performed because her family refused, owing to the allergic constitution of the patient and the high risk of an allergic reaction to the contrast agent.

Fig. 3

Repeated ECG performed on April 28, 2022 (sinus rhythm, ST-segment elevation in leads I, II, and avL fell back to baseline, T-wave inversion in leads I and avL, ST-segment depression in leads V1-V4 returned to baseline, and T-wave inversion became upright compared with pre-treatment ECG)

Table 1 Allergen test results Fig. 4

Lung CT on April 28, 2022, suggesting interstitial pulmonary edema; repeated lung CT on May 13, 2022 shows resolution of pulmonary edema

Fig. 5

Cardiac ultrasound on April 28, 2022 (A): full left-sided heart (LA 35 mm/LV 55 mm), low left heart systolic function (LVEF, 29.1%; FS, 13.6%), mild mitral and tricuspid regurgitation. Repeated bedside cardiac ultrasound on May 16, 2022 (B) shows normal heart size and structure, as well as normal cardiac function (LVEF, 70%; FS, 39%). On April 28, 2022 (C/D), echocardiography showed wall motion abnormalities namely a segmental hypokinesia in the lateral wall of left ventricle in the apical four-chamber view, consistent with ECG finding, suggesting the presence of anterior descending diagonal branch lesion (considering that ECG STaVL↑>STI↑, the anterior descending diagonal branch lesion was more likely)

Treatment

The treatment mainly included anti-allergic, anti-shock, and management of acute myocardial ischemia, including methylprednisolone, aspirin, clopidogrel, atorvastatin, low molecular weight heparin calcium subcutaneous injection, pantoprazole, nitroglycerin infusion, and maintenance of water-electrolyte acid-base balance. The patients’s symptoms resolved with the above-mentioned therapies, and the results of repeated bedside cardiac ultrasound, lung CT, myocardial enzyme spectrum, cTnI, and ECG findings were all normal. Elective coronary angiography performed on May 10, 2022 revealed normal coronary arteries (Fig. 6). There were no adverse reactions or accidents during hospitalization.

Fig. 6

Elective coronary angiography findings of the patient on May 10, 2022 (Figure A (left coronary right cephalad)/Figure B (left coronary right pedicle)/Figure C (right coronary left anterior oblique)/Figure D (left coronary spider, showing no stenosis in the anterior descending, gyral branch, and right coronary arteries, with flow TIMI grade 3)

Diagnosis

The patient was diagnosed with Type I Kounis syndrome. After vaccination, the patient developed an allergic reaction along with dyspnea and typical angina pectoris lasting up to 30 minutes. Myocardial enzyme profile and troponin levels were significantly increased, and the dynamic evolution of the electrocardiogram and cardiac ultrasound findings supported the diagnosis of acute myocardial infarction. Allergen profiling indicated an allergic constitution. The clinical picture was suggestive of a type II acute myocardial infarction due to allergy-induced spasm of the coronary arteries. The patients condition significantly improved after active treatment with anti-allergic, anti-coronary spasm, and anti-platelet therapy).​ The clinical picture was consistent with the diagnosis of type I Kounis syndrome.

Follow up

​ The patient was discharged from the hospital on 13 May 2022 and has not experienced any discomfort during the follow-up period. On August 5, 2022, cardiac magnetic resonance imaging (CMR) showed no signs of myocarditis or myocardial edema, no spherical changes in the heart tip, and no significant abnormalities in systolic and diastolic function. ​A repeated ECG performed on 04 December 2022 showed no abnormalities.​