Giant T wave inversion

Cardiac memory: an under-recognised cause of deep T wave inversion in a patient presenting with chest pain

T wave inversion (TWI) has many differential diagnoses with acute myocardial ischaemia being the highest on the list of potential causes. Cardiac T wave memory is a benign, under-recognised and clinically important phenomenon seen after periods of altered ventricular conduction. After normal ventricular conduction is restored, the T wave 'remembers' and mirrors the direction of the wide QRS complex. Therefore, negative T waves are seen in leads that had negative wide QRS complexes. We describe the case of a 60-year-old truck driver with chest pain, deep TWI and traditional cardiovascular risk factors. After ruling out significant myocardial ischaemia, it was crucial to determine the cause of his T wave changes to provide reassurance and provide commercial license medical clearance. While it is currently a diagnosis of exclusion, it remains an important clinical entity for clinicians to recognise to provide an explanation for certain T wave changes to avoid future unnecessary cardiac testing.

Apical hypertrophic cardiomyopathy treated as ST-elevation myocardial infarction

Electrocardiographic changes resulting from apical hypertrophic cardiomyopathy may mimic an acute coronary syndrome. A 67-year-old Sudanese male without cardiac risk factors presented to hospital with chest pain and electrocardiographic findings of septal ST-segment elevation, ST-segment depression in V4-V6, and diffuse T-wave inversion. He was treated as an acute ST-elevation myocardial infarction with thrombolytics. There was no cardiac biomarker rise and coronary angiography did not reveal evidence of significant coronary arterial disease. Ventriculography, transthoracic echocardiography, and cardiac magnetic resonance imaging were consistent with apical hypertrophic cardiomyopathy. The patient was discharged three days later with outpatient cardiology follow-up. We highlight the clinical and electrocardiographic findings of apical hypertrophic cardiomyopathy, with an emphasis on distinguishing this from acute myocardial infarction.

Cardiac and non-cardiac causes of T-wave inversion in the precordial leads in adult subjects: A Dutch case series and review of the literature

AIM: To describe the electrocardiographic (ECG) phenomena characterized by T-wave inversion in the precordial leads in adults and to highlight its differential diagnosis.

METHODS: A retrospective chart review of 8 adult patients who were admitted with ECG T-wave inversion in the anterior chest leads with or without prolongation of corrected QT (QTc) interval. They had different clinical conditions. Each patient underwent appropriate clinical assessment including investigation for myocardial involvement. Single and multimodality non-invasive, semi-invasive and invasive diagnostic approach were used to ascertain the diagnosis. The diagnostic assessment included biochemical investigation, cardiac and abdominal ultrasound, cerebral and chest computed tomography, nuclear medicine and coronary angiography.

RESULTS: Eight adult subjects (5 females) with a mean age of 66 years (range 51 to 82) are analyzed. The etiology of T-wave inversion in the precordial leads were diverse. On admission, all patients had normal blood pressure and the ECG showed sinus rhythm. Five patients showed marked prolongation of the QTc interval. The longest QTc interval (639 ms) was found in the patient with pheochromocytoma. Giant T-wave inversion (≥ 10 mm) was found in pheochromocytoma followed by electroconvulsive therapy and finally ischemic heart disease. The deepest T-wave was measured in lead V₃ (5 ×). In 3 patients presented with mild T-wave inversion (patients 1, 5 and 4 mm), the QTc interval was not prolonged (432, 409 and 424 msec), respectively.

CONCLUSION: T-wave inversion associated with or without QTc prolongation requires meticulous history taking, physical examination and tailored diagnostic modalities to reach rapid and correct diagnosis to establish appropriate therapeutic intervention.

Factors predicting coronary artery disease in patients with giant negative T waves

Seventy-four patients with giant negative T waves were studied to determine which electrocardiographic variables predicted the presence of coronary artery disease. The absence of left ventricular hypertrophy and the presence of symmetric T-wave inversion predicted coronary artery disease.

Large T wave inversion and QT prolongation associated with pulmonary edema: a report of nine cases

OBJECTIVES

The purpose of this study is to describe a new clinical electrocardiographic phenomenon characterized by diffuse symmetrical T wave inversion and QT prolongation after recovery from an episode of cardiogenic but nonischemic pulmonary edema.

BACKGROUND

A variety of clinical conditions, but not acute pulmonary edema, have been previously associated with giant negative T waves and QT prolongation in the postevent electrocardiogram.

METHODS

In nine patients not suspected of having ischemic heart disease, new large or global T wave inversion with QT prolongation was observed after resolution of acute cardiogenic pulmonary edema. Each patient underwent detailed clinical evaluation including testing for myocardial injury and a coronary ischemic etiology.

RESULTS

There were seven women and two men with ages ranging from 32 to 79 years. The etiology of pulmonary edema was diverse, but acute myocardial infarction and significant coronary artery disease were ruled out in each case. During the index event, most patients had elevated blood pressure, sinus tachycardia, minimal nonspecific ST and T wave changes and normal QT intervals. Large inverted T waves with marked prolongation of the QT intervals evolved within 24 h after clinical stabilization. The electrocardiographic changes gradually resolved in one week. There was no in-hospital mortality.

CONCLUSIONS

Acute cardiogenic but nonischemic pulmonary edema may cause deep T wave inversion and QT prolongation after resolution of the symptoms. The repolarization abnormalities may last for several days. These electrocardiographic changes do not adversely effect short-term prognosis.

Giant T wave inversion associated with severe aortic regurgitation

Two patients with haemodynamically significant aortic regurgitation and angiographically normal coronary arteries developed giant T wave inversion. The T wave abnormality partially resolved in both, following valve replacement in one and medical treatment in the other. This unusual electrocardiographic appearance may be related to myocardial ischaemia caused by increased left ventricular wall stress and changes in phasic coronary blood flow, abnormalities in cerebral perfusion associated with severe aortic regurgitation, or to coincidental neurological disease.

Transient giant negative T wave in acute anterior myocardial infarction predicts R wave recovery and preservation of left ventricular function

OBJECTIVE

To investigate the value of a giant negative T wave (> or = 1.0 mV) in precordial leads of 12-lead electrocardiograms in the acute phase of Q wave myocardial infarction as a predictor of myocardial salvage.

METHODS

Coronary angiographic and electrocardiographic findings, left ventricular ejection fraction in the chronic stage, and levels of cardiac enzymes were compared in patients with myocardial infarction with (group GNT, n = 31) and without (group N, n = 20) a giant negative T wave. GNT patients were divided into two subgroups according to the presence (GNT:R[+], n = 10) or absence (GNT: R[-], n = 21) of R wave recovery with an amplitude > or = 0.1 mV in at least one lead that had shown Q waves.

RESULTS

The maximum level of creatine kinase and the total creatine kinase were lower in group GNT compared with group N (P < 0.05). The left ventricular ejection fraction was higher in group GNT than in group N (P < 0.05). The maximum creatine kinase and total creatine kinase were lower in GNT:R(+) than in GNT:R(-) (P < 0.01). The left ventricular ejection fraction was higher in GNT:R(+) than in GNT:R(-) (P < 0.01). The frequency of R wave recovery was significantly higher when giant negative T waves appeared within 100 h of myocardial infarction or when the maximum potential was > or = 1.4 mV. The appearance of a giant negative T wave > or = 1.4 mV had a sensitivity of 90%, a specificity of 71.4%, a diagnostic accuracy of 77.4%, a positive predictive value of 60%, and a negative predictive value of 93.8% for prediction of R wave recovery.

CONCLUSIONS

The appearance of a giant negative T wave, especially within 100 h of the onset of myocardial infarction, with a maximum potential of > or = 1.4 mV, may predict a reappearance of the R wave and a better left ventricular function in patients in the chronic stage of anterior myocardial infarction.

Giant negative T waves after maxillofacial surgery

A patient developed strongly negative T waves following anesthesia for maxillofacial surgery. The electrocardiogram was normal preoperatively, except for a single premature ventricular depolarization, and no abnormalities were noted during the operation. Postoperatively, the T wave gradually inverted in almost all leads and approached the criterion of -10 mm for giant negative T waves in V3 2 days postoperatively. The T wave returned to normal approximately 4 months later. Although the T-wave inversion in this patient may have been caused by surgical trauma to the sympathetic nerve supply to the heart or by myocardial infarction, the exact cause remains undetermined.

Hypocalcemic Torsades de Pointes

Torsades de pointes is a unique form of ventricular tachycardia that occurs in the presence of prolonged QT interval. Many predisposing factors have been identified. A classical form of torsades de pointes occurring in the presence of hypocalcemia and prolonged QT interval in an elderly woman is reported. In this patient the QT prolongation was markedly rate-dependent. Hypocalcemia was a postoperative complication following removal of parathyroid adenoma, performed earlier for hyperparathyroidism. Torsades de pointes did not recur after normalization of serum calcium. To the authors' knowledge, this is the first electrocardiographic documentation of hypocalcemic torsades de pointes.

The QT interval historically treated

The growth of knowledge of the QT interval of the ECG is reviewed. 1980 was the centennial of the first careful measurements of Burdon-Sanderson and Page, and also the 60th anniversary of Bazett's contribution that established a predictable relation of the QT to heart rate in normal subjects. The waxing and waning of interest in the QT among clinical cardiologists appear to have been related to a low sensitivity and specificity of abnormal QT/rate ratios in many clinical diseases. The QT duration has been established as a valuable measurement, and sometimes the patterns may be nearly pathognomonic of electrolyte disturbances. Alterations from a predicted normal mean may give a clue to disease. The importance of transient dissociation of the predicted QT from the measured QT with rapid changes in heart rate deserves further emphasis. In the publication of data on the duration of QT, the reporting only of the corrected QT (QTc), the index of Bazett, conveys an incomplete picture of the nature of the changes. The prolonged QT pattern in adults should be suspected of being related to drugs first, except when a neurogenic cause is apparent. The idiopathic hereditary syndrome still defies a completely adequate explanation, though neurogenic influences are overtly important. No universal management has been established.