On 2017 May 15, Preben Berthelsen commented:

During light chloroform anaesthesia, 1 of 2500 patients succumbed to sudden cardiac syncope – usually when the skin was incised.

1 in 2000 has a genetically determined defect in repolarisation of the myocardium – the long-QT syndrome. Such patients may likewise succumb to sudden cardiac arrest when experiencing emotional and/or physically stressing events.

The striking similarity in the mode of dying – the sudden unexpected arrest of the heart during stress - makes it a fair hypothesis/assumption that patients dying during chloroform anaesthesia were individuals with an inherited or acquired delay in myocardial repolarisation.

No ECG recording from a patient dying during chloroform anaesthesia exists so the hypothesis cannot be proven.

For 100 years, chloroform was used to alleviate labour pain – remarkably with no maternal deaths. A recent investigation has shown an oestradiol-mediated shortening of the QT-interval - both in normal women and in women with the inherited form of delayed myocardial repolarisation - providing a likely explanation for the safety of the obstetric use of chloroform and lends credence to the hypothesis presented in the paper.

P.G.Berthelsen. MD. Charlottenlund, Denmark

On 2017 May 15, Preben Berthelsen commented:

During light chloroform anaesthesia, 1 of 2500 patients succumbed to sudden cardiac syncope – usually when the skin was incised.

1 in 2000 has a genetically determined defect in repolarisation of the myocardium – the long-QT syndrome. Such patients may likewise succumb to sudden cardiac arrest when experiencing emotional and/or physically stressing events.

The striking similarity in the mode of dying – the sudden unexpected arrest of the heart during stress - makes it a fair hypothesis/assumption that patients dying during chloroform anaesthesia were individuals with an inherited or acquired delay in myocardial repolarisation.

No ECG recording from a patient dying during chloroform anaesthesia exists so the hypothesis cannot be proven.

For 100 years, chloroform was used to alleviate labour pain – remarkably with no maternal deaths. A recent investigation has shown an oestradiol-mediated shortening of the QT-interval - both in normal women and in women with the inherited form of delayed myocardial repolarisation - providing a likely explanation for the safety of the obstetric use of chloroform and lends credence to the hypothesis presented in the paper.

P.G.Berthelsen. MD. Charlottenlund, Denmark