This is the first of three cases with a theme of T wave changes...
Vladimir is a 77 year old man with a history of hypertension and mitral valve replacement that requires anticoagulation with warfarin. He came to hospital because of sudden onset of headache and neck stiffness. The ECG on arrival is shown in Figure 1. Blood test results showed a normal serum troponin concentration and normal serum electrolyte concentrations.
The main findings are:
- The rhythm is regular and the ventricular rate is 60 beats per minute. The regular rate rules out atrial fibrillation. The isoelectric line has high frequency low amplitude artefacts that could mask (low amplitude P waves). However since there are no clearly defined P waves we will rule out sinus rhythm. The width of the QRS complexes is at the upper limit of normal, which indicates that the rhythm originates from the (atrioventricular) junction. The underlying rhythm is thus a junctional rhythm.
- The T wave in Lead I is flattened and there is marked T wave inversion in the inferior leads and in Leads V2 to V6. A feature of these inverted T waves is their wide base (of about 10 mm). The width of T waves is usually not assessed separately, as it is included in the measured QT interval. T wave inversions are usually classified by amplitude (depth) rather than width: inverted T waves with a amplitude that is 5 mm (10 mm according to some) or more are termed"giant T wave inversion" (GTWI).
The results of brain CT scans and cerebral angiography are shown in Figure 2.
The main radiological findings are those of subarachnoid haemorrhage (SAH) without a detectable cerebral aneurysm. The ECG changes in this case are secondary to the subarachnoid haemorrhage.
The first report that described an association between ECG changes and cerebrovascular accidents was published in 1954 (Burch GE, Meyers R, Abildskov JA. A new electrocardiographic pattern observed in cerebrovascular accidents. Circulation 1954; 9:719-723): "..... distinctive electrocardiographic pattern [was] encountered in patients with cerebrovascular accidents, consisting primarily of T waves of considerable amplitude and width [the T waves were often inverted, but could be upright], long Q-T interval,and large U waves.....".
The changes that may be seen in the ECG in persons with SAH are:
- increased P wave amplitude ("peaked" P waves)
- short PR interval
- large amplitude R waves
- ST elevation or ST depression
- T wave notching
- widened T waves that are often inverted but can be upright
- large U waves
- prolonged QT interval
- supraventricular rhythms: atrial ectopics, atrial fibrillation, supraventricular tachycardia
- ventricular rhythms: ventricular ectopic beats, non sustained ventricular tachycardia, Torsades de Pointes, ventricular fibrillation
The causes of GTWI in ECGs include:
- Central nervous disorders such as stroke, subarachnoid or intracranial haemorrhage or seizure. The QT interval will usually be prolonged with central nervous system disorders and there is often T wave broadening
- Stokes-Adams attacks (especially when due to severe bradycardia or complete AV block)
- Acute ischaemia/coronary artery disease
- Post-tachycardia syndrome
- Massive pulmonary embolism
- Acute pulmonary oedema
- Apical hypertrophic cardiomyopathy (Yamaguchi syndrome)
- Takotsubo cardiomyopathy
- Wellens' syndrome
Harries AD. Subarachnoid haemorrhage and the electrocardiogram - a review. PostgradMed J. 1981; 57:294-296
Chatterjee S. ECG changes in subarachnoid haemorrhage: a synopsis. Neth Heart J 2011; 19:31–34 DOI 10.1007/s12471-010-0049-1
Beydilli I, Korkmaz I, Yilmaz F et al. Subarachnoid hemorrhage mimicking myocardial infarction. The Internet Journal of Emergency Medicine Volume 7 Number 2 P1 - 4
Bones and the Radiologist
Another cartoon featuring Bones, drawn by Rowan (an anaesthetic registrar who worked in the Casualty Department of the Preston and Northcote Community Hospital in the early 1980s). Bones believed in emotionally based indications for investigations, unlike the evidence based indications that we try to use today.