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QTc prolongation prior to angiography predicts poor outcome and associates significantly with lower left ventricular ejection fractions and higher left ventricular end-diastolic pressures.

van der Bijl P, Heradien M, Doubell A, Brink P - Cardiovasc J Afr (2012)

Bottom Line: QT prolongation on the surface ECG is associated with sudden cardiac death.LQTc was significantly associated with mortality (LQTc 12% vs NQTc 1.7%; p < 0.01), and with lower but normal LVEF (LQTc 52.9 ± 15.4% vs NQTc 61.6 ± 13.6%; p < 0.01), higher LVEDP at LVEF > 45% (LQTc 19.2 ± 9.0 mmHg vs NQTc 15.95 ± 7.5 mmHg; p < 0.05), hypercholesterolaemia and a negative family history of IHD.QTc also associated strongly with left ventricular systolic and diastolic dysfunction, hypercholesterolaemia and a negative family history of IHD.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Cardiology, Department of Medicine, Stellenbosch University and Tygerberg Academic Hospital, Western Cape, South Africa.

ABSTRACT

Background: QT prolongation on the surface ECG is associated with sudden cardiac death. The cause of QT prolongation in ischaemic heart disease (IHD) patients remains unknown, but may be due to a complex interplay between genetic factors and impaired systolic and/or diastolic function through as yet unexplained mechanisms. It was hypothesised that QT prolongation before elective coronary angiography is associated with an increased mortality at six months.

Methods: Complete records of 321 patients who underwent coronary angiography were examined for QT interval corrected for heart rate (QTc), left ventricular ejection fraction (LVEF), left ventricular end-diastolic pressure (LVEDP) and known ischaemic heart disease risk factors. Patients were designated long QTc (LQTc) when they had prolonged QTc intervals or normal QTc (NQTc) when the QTc interval was normal. Patients with atrial fibrillation, bundle branch blocks, no ECG in the 24 hours before angiography, or a creatinine level > 200 µmol/l were excluded. Survival was determined telephonically at six months.

Results: Twenty-eight per cent of the total population had LQTc. During follow up, 15 patients (4.7%) died suddenly, 73% of whom had a LQTc. LQTc was significantly associated with mortality (LQTc 12% vs NQTc 1.7%; p < 0.01), and with lower but normal LVEF (LQTc 52.9 ± 15.4% vs NQTc 61.6 ± 13.6%; p < 0.01), higher LVEDP at LVEF > 45% (LQTc 19.2 ± 9.0 mmHg vs NQTc 15.95 ± 7.5 mmHg; p < 0.05), hypercholesterolaemia and a negative family history of IHD.

Conclusion: In patients with sinus rhythm and normal QRS width, QTc prolongation before coronary angiography predicted increased mortality at six months. QTc also associated strongly with left ventricular systolic and diastolic dysfunction, hypercholesterolaemia and a negative family history of IHD.

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Mean total serum cholesterol versus QTc interval for NQTc and LQTc groups of patients.
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Figure 5: Mean total serum cholesterol versus QTc interval for NQTc and LQTc groups of patients.

Mentions: LQTc patients had normal LVEF but lower than that of the NQTc cohort (LQTc: 52.9 ± 15.4% vs NQTc: 61.6 ± 13.6%; p < 0.01) (Fig. 3) and higher LVEDP at LVEF > 45% (LQTc: 19.2 ± 9.0 mmHg vs NQTc: 15.9 ± 7.5 mmHg; p < 0.05) (Fig. 4). The LQTc cohort also had significantly higher serum cholesterol levels than the NQTc cohort (Fig. 5).


QTc prolongation prior to angiography predicts poor outcome and associates significantly with lower left ventricular ejection fractions and higher left ventricular end-diastolic pressures.

van der Bijl P, Heradien M, Doubell A, Brink P - Cardiovasc J Afr (2012)

Mean total serum cholesterol versus QTc interval for NQTc and LQTc groups of patients.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3721884&req=5

Figure 5: Mean total serum cholesterol versus QTc interval for NQTc and LQTc groups of patients.
Mentions: LQTc patients had normal LVEF but lower than that of the NQTc cohort (LQTc: 52.9 ± 15.4% vs NQTc: 61.6 ± 13.6%; p < 0.01) (Fig. 3) and higher LVEDP at LVEF > 45% (LQTc: 19.2 ± 9.0 mmHg vs NQTc: 15.9 ± 7.5 mmHg; p < 0.05) (Fig. 4). The LQTc cohort also had significantly higher serum cholesterol levels than the NQTc cohort (Fig. 5).

Bottom Line: QT prolongation on the surface ECG is associated with sudden cardiac death.LQTc was significantly associated with mortality (LQTc 12% vs NQTc 1.7%; p < 0.01), and with lower but normal LVEF (LQTc 52.9 ± 15.4% vs NQTc 61.6 ± 13.6%; p < 0.01), higher LVEDP at LVEF > 45% (LQTc 19.2 ± 9.0 mmHg vs NQTc 15.95 ± 7.5 mmHg; p < 0.05), hypercholesterolaemia and a negative family history of IHD.QTc also associated strongly with left ventricular systolic and diastolic dysfunction, hypercholesterolaemia and a negative family history of IHD.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Cardiology, Department of Medicine, Stellenbosch University and Tygerberg Academic Hospital, Western Cape, South Africa.

ABSTRACT

Background: QT prolongation on the surface ECG is associated with sudden cardiac death. The cause of QT prolongation in ischaemic heart disease (IHD) patients remains unknown, but may be due to a complex interplay between genetic factors and impaired systolic and/or diastolic function through as yet unexplained mechanisms. It was hypothesised that QT prolongation before elective coronary angiography is associated with an increased mortality at six months.

Methods: Complete records of 321 patients who underwent coronary angiography were examined for QT interval corrected for heart rate (QTc), left ventricular ejection fraction (LVEF), left ventricular end-diastolic pressure (LVEDP) and known ischaemic heart disease risk factors. Patients were designated long QTc (LQTc) when they had prolonged QTc intervals or normal QTc (NQTc) when the QTc interval was normal. Patients with atrial fibrillation, bundle branch blocks, no ECG in the 24 hours before angiography, or a creatinine level > 200 µmol/l were excluded. Survival was determined telephonically at six months.

Results: Twenty-eight per cent of the total population had LQTc. During follow up, 15 patients (4.7%) died suddenly, 73% of whom had a LQTc. LQTc was significantly associated with mortality (LQTc 12% vs NQTc 1.7%; p < 0.01), and with lower but normal LVEF (LQTc 52.9 ± 15.4% vs NQTc 61.6 ± 13.6%; p < 0.01), higher LVEDP at LVEF > 45% (LQTc 19.2 ± 9.0 mmHg vs NQTc 15.95 ± 7.5 mmHg; p < 0.05), hypercholesterolaemia and a negative family history of IHD.

Conclusion: In patients with sinus rhythm and normal QRS width, QTc prolongation before coronary angiography predicted increased mortality at six months. QTc also associated strongly with left ventricular systolic and diastolic dysfunction, hypercholesterolaemia and a negative family history of IHD.

Show MeSH
Related in: MedlinePlus