A 52-year-old man presented with chest pain for 3 days and 2 hours on July 30, 2021. Three days prior, the patient suffered from chest pain, which was a paroxysmal dull pain that was located in the lower section of the sternum and lasted more than 10 seconds to 2 minutes with no connection to physical activity. The symptom was not accompanied by palpitations, shortness of breath, dizziness, or hemoptysis. The outpatient treatment following the "coronary heart disease" treatment had been poor. Symptoms occurred for another 2 hours, with the same nature as before. The patient was then transferred from the emergency department to our department for systematic diagnosis and treatment. The patient had hypertension for 6 months and took amlodipine tablets (5 mg) once daily. His maximum blood pressure was to 170/102 mmHg and was not monitored. He denied use of any tobacco or alcohol and did not have other known chronic diseases. There were no similar diseases or any other genetic history of disease in his family.
The patient’s vital signs were normal upon admission. On physical examination: the patient’s body temperature was 36.5°C, pulse rate: 77/min, respiratory rate: 18/min, blood pressure: 137/91 mmHg, weight: 62 kg, and height: 1.68 meters. The patient had a clear mind, upright posture, no cyanosis of lips, no dilation of jugular veins, and there was no negative sign of hepatic jugular venous reflux. The respiratory sound of both lungs was clear, there were no dry or wet rales. The cardiac boundary was normal with a heart rate of 77/min. The heart rhythm was uniform, and there was no murmur in the auscultation area of each valve. The abdomen was flat and soft, without tenderness and rebound pain, and the bowel sound was normal. The radial arteries of both upper limbs had consistent pulsation. The pulse of dorsalis pedis artery of both lower limbs was consistent. There was no edema in either of the lower limbs. Auxiliary examination results from the emergency department showed no detectable changes in myocardial enzymes, myoglobin, serum troponin T, blood routine, coagulation function, liver and kidney function, serum glucose, and or electrolytes. Electrocardiographic recordings during sinus rhythm showed an ST change (Figure 1a).
Admission diagnosis: Causes of chest pain to investigate: CHD,acute coronary syndrome (ACS),and hypertension grade 2, at high risk. On the sixth hour post-admission, re-examination of myocardial enzyme and serum troponin T were normal. The electrocardiogram (ECG) showed no change from before. No abnormalities were found in thyroid function or glycosylated hemoglobin. Echocardiography results showed: 1. No significant abnormalities in the size of each chamber in the heart; 2. Low calcification in the right and non-coronary aortic valves; 3. Tricuspid valve micro regurgitation; 4. No obvious abnormalities in the left ventricular overall contractile function. On the second and third day in the hospital, the patient underwent CTA examination of the coronary arteryand CAG, respectively. Coronary artery computed tomography angiography (CTA; Figure 2a, b) and coronary angiography (CAG; Figure 3a–d) showed the absence of the left coronary artery and 20% stenosis in the right coronary artery. The distal blood vessel supplied blood to the left heart. The MB was confined to the second right ventricular branch (Figure 2b,Figure 3c, d). CAG showed a TIMI glow of grade 3.
Definite diagnosis: 1. Absence of left coronary artery (type R-I) 2. MB (the second right ventricular branch) 3. Coronary atherosclerosis 4. Hypertension grade 2, at high risk. During his hospitalization, the patient was treated with dirthiazem (90 mg, qd), fosinopril (10 mg, qd), atorvastatin (20 mg, qn), and aspirin (100 mg, qd). Amlodipine tablets were stopped, which is a secondary prevention of CHD. After 3 days, the patient’s chest pain disappeared. Re-examination of the ECG indicated that it was normal. The patient improved and was discharged on August 9, 2021.