Table 1

JRCALC Indications/contraindications for prehospital thrombolysis

Contraindications to prehospital thrombolysisReduced level of consciousness (The patient must be able to give consent to thrombolytic therapy).
Dementia (increased risk of stroke1).
Age greater than 75 years (increased risk of stroke2).
Continuous symptoms for less than 30 minutes or more than 6 hours (Myocardial salvage is limited beyond 6 hours3).
Suspected aortic dissection (risk of severe bleeding).
Bradycardia of 50 beats per minute (bpm) or less (patient may require pacing).
Tachycardia of 140 bpm or more (arrhythmia may be mimicking ECG changes synonymous with AMI).
Systolic blood pressure (SBP) 80 mm Hg or less (risk of further hypotension if streptokinase administered).
SBP 160 mm Hg or more (increased risk of stroke4).
Pregnancy, or delivery within past two weeks (there are no data on fetal safety when thrombolytic therapy is administered during pregnancy, and there is also a risk of maternal bleeding in the first week postpartum).
Peptic ulcer within the last 6 months (increased risk of bleeding).
Previous stroke, or disability from a previous stroke (increased risk of stroke).
Cerebral tumour (increased risk of bleeding).
Active bleeding or known bleeding disorder (increased risk of severe bleeding).
Recent blood loss, except for normal menstruation (menstrual bleeding that is not due to haematological abnormalities5).
Anticoagulant therapy (risk of severe bleeding).
Surgical operation, tooth extractions, significant trauma, or head injury within the past 4 weeks (increased risk of bleeding).
Previous administration of streptokinase (antigenic and allergenic properties of streptokinase will reduce efficacy6).
Chest compression for resuscitation for a period of longer than 5 minutes during the presenting incident (increased risk of bleeding due to traumatic injury).
Liver failure, renal failure, or any other severe systemic illness (for example, chemotherapy for cancer) (increased risk of bleeding).
Indications to prehospital thrombolysis:ST segment elevation of 2 mm or more (0.08s after the J point) in at least two standard leads or at least two contiguous precordial leads, not including V1.
QRS width 0.14 mm or less, and bundle branch block absent from the tracing.
NO atrio-ventricular block greater than 1st degree (if necessary after treatment with intravenous atropine).