A 27-year-old man of North African descent attended the emergency room of our tertiary percutaneous coronary intervention centre because of chest pain. Since 12 h, he had experienced severe retrosternal chest pain with sweating, nausea, and vomiting. Electrocardiography demonstrated ST-elevation in the anterior leads (Figure ). Detailed history revealed that in the hours prior to presentation, he had been recreationally using high amounts of N2O by inhalation from balloons. For the last 24–48 h, he had been sleep-deprived and, while sitting in a car, he had inhaled approximately 3.3 kg (or 420 balloons) of N2O and smoked 4 joints of cannabis. The patient had not experienced recent trauma, had no co-morbidities and was not under any prescription. He had never experienced chest pain before, there were no signs of acute heart failure. Besides smoking nicotine and cannabis, he did not have any other cardiovascular risk factors. There was no family history of coronary disease or sudden cardiac death. Drug screening upon presentation was positive for tetrahydrocannabinol (THC). Patient admitted to regularly smoke cannabis but denied consumption of alcohol or any other recreational drugs.\nAs per hospital protocol, he received 180 mg ticagrelor orally, 300 mg aspirin intravenously (i.v.) and 5000 EH heparin i.v. and was referred for immediate coronary angiography (CAG). This showed a normal aspect of the left main, right coronary and circumflex artery. The distal left anterior descending artery (LAD) was totally occluded, and thrombus was angiographically visible in the proximal segment, with maintained flow (TIMI 3) (Figure and ). Despite successful wire passage into the distal LAD and multiple balloon dilatations, no recanalization was achieved. Therefore, mechanical thrombectomy by means of AngioJet was attempted without distal recanalization, nor angiographical resolution of the proximal thrombus. Optical coherence tomography of the proximal LAD confirmed the presence of residual thrombus but excluded atherosclerotic media thickening. Plaque/endothelial erosion underneath the thrombus could not be excluded (Figure and ). Because of a minimal lumen area of 10.75 mm2 no further intervention was undertaken. The procedure was discontinued, and the patient received tirofiban i.v. for 48 h, on top of standard dual antiplatelet therapy (DAPT: ticagrelor and aspirin).\nThe first high-sensitive troponin T and CK-MB levels were 0.418 μg/L and 77 μg/L, peaking at 5.35 μg/L (upper limit of reference range: 0.014 μg/L) and >300 μg/L (upper limit of reference range: 7.6 μg/L). Transthoracic echocardiogram (TTE) showed a reduced (30–40%) left ventricular ejection fraction (LVEF) with apical and mid septal akinesia, a normal right ventricular function and no valvular abnormalities (). Migration of a venous thromboembolism due to intracardiac right-left shunt was excluded by using right-sided contrast. Vitamin B12 (114 pmol/L; reference range: 160–700 pmol/L), folic acid (7.7 nmol/L; 8.8–40 nmol/L), and homocysteine (205 μmol/L; <15 μmol/L) levels were measured upon admission.\nAfter 5 days, serum homocysteine levels had decreased to 86 μg/L. Additional analysis excluded the presence of a methylenetetrahydrofolate reductase (MTHFR)-gene polymorphism. To evaluate the effect of the initiated antiplatelet therapy CAG was repeated after 7 days. The size of the thrombus in the proximal LAD was slightly reduced, but the distal LAD remained occluded. (Figure and ). After initiation of heart failure medication, he was discharged with the advice to take DAPT for 1 year, discontinue drug abuse and take oral folic acid and vitamin B12 supplementation. Upon discharge persistent ST-elevation with negative T- (V2–V6) and pathological Q-waves (V2–V6) in the anterior leads was shown on the electrocardiogram (Figure ).\nAfter 3 months, a repeat TTE showed improvement of LVEF (53%), with remaining anteroseptal wall motion abnormalities (). He did not report recurrent angina or symptoms of heart failure.
Sudden-onset chest pain for 1 d.\nA 29-year-old man complained of sudden precordial pain with no remission for 1 d prior to hospital admission but denied hemoptysis, dyspnea, or syncope. He sought evaluation and was admitted for the purpose of intensive examination and treatment.\nThe patient had been addicted to N2O for 1 year; as a result, peripheral neuropathy had occurred and was treated with vitamin B12 (Vit B12). His medical history included poor blood glucose control and anxiety. However, he had no history of thrombosis, malignant tumor, recent trauma, or prolonged air travel.\nThe patient has smoked over 13 pack-years and did not have alcoholism or a positive family history.\nThe initial assessment revealed that the patient was overweight and fragile, with a body mass index of 31.12 kg/m2, temperature of 36.3 °C, blood pressure of 110-120/70-80 mmHg, heart rate over 110 beats/min, respiratory rate over 30 breaths/min, and pulse oximetry of 93% when the fraction of inspired oxygen was 49%. Moreover, the physical examination indicated diminished breath sounds on both sides and the accentuation of pulmonic second sounds.\nLaboratory data showed a high leukocyte count and an increased hemoglobin level, suggested abnormal liver biochemistry and hyperlipidemia, and revealed HHcy (24.12 µmol/L), high Vit B12 (734 µmol/L), and normal folate (14.39 nmol/L). The results of the protein S, protein C, anti-thrombin III antibody, anti-cardiolipin antibody, lupus anticoagulant, anti-β2gp1 autoantibody, and other autoantibodies were within normal limits. The clotting profile was normal, other than the D-dimer value (1.13 mg/L), and thrombophilia screening was negative. As markers in the risk stratification of PE, the levels of brain natriuretic peptide (BNP) and cardiac troponin I (CTnI) were 533 pg/mL and 0.334 ng/mL, respectively. Arterial blood gas levels measured with an oxygen concentration of 49% showed the following: pH, 7.44; PaCO2, 30 mmHg; and PaO2, 74 mmHg.\nAn electrocardiogram (ECG, Figure ) showed sinus tachycardia with typical changes on SIQIIITIII (S wave in the aVL lead, Q wave and T wave in the III lead). Ultrasonic cardiogram demonstrated right ventricular enlargement with left ventricular compression. Color Doppler scans were used to explore femoral, popliteal, and calf muscular venous thrombosis in the right extremity. Computed tomographic pulmonary angiography (CTPA) revealed occlusion of the pulmonary artery trunk, lobar artery, and arterial branches on both sides and signs of increased right heart load (Figure and ).