Cardiac Rhythm Management

When I was cardiology registrar, drugs available for rhythm management were digoxin, quinidine and procaineamide.  During my years as a cardiologist, noteable additions were amiodarone, flecainide and sotalol.
One recollection that I have is the recognition of the entity rate-related cardiomyopathy.  Two memorable patients were:

a) B.B., a 58yr old barrister, presented with dilated cardiomyopathy, cardiac failure and atrial fibrillation.  I attributed his disease, probably erroneously, to excess alcohol consumption.   Eventually he developed episodes of ventricular tachycardia and was given amiodarone.   Not only did this prevent recurrences of VT, but it also resulted in unexpected reversion to sinus rhythm and subsequent 'disappearance' of his cardiomyopathy!
b) J.D., a 25yr old man, presented with a largely regular tachycardia of around 140/min, revealed on ECG to be bidirectional ventricular tachycardia with occasional normal sinus beats interspersed.   He claimed that his heart rate had "always been at this level".  The echocardiogram showed gross cardiac dilatation with impaired LV and RV function.   He returned to his native UK soon after and was given amiodarone which reverted the tachycardia to SR.   There was return of cardiac size and function to normal.

Defibrillation and Cardioversion

Until the mid 1960s, the management of ventricular fibrillation in hospital (outside of the operating theatre), relied on the availability of a single AC-powered device shown below.   This defibrillator was kept in the Cardiothoracic office, at the top of the ramp corridor leading to the 210-block.  Access to the device required a call to either Jim Baird or Tim Savage.  There was often considerable time delay before Jim or Tim arrived with the defibrillator and successful defibrillation depended on the length of this delay and the management of the patient in the interim.

 

 

Closed-chest cardiac compression did not 'arrive' at the hospital until around 1963.  I clearly recall an incident in the Casualty Department in the first quarter of 1962.  I was Casualty HS and Ted Watson was the Senior Cas Officer when a young apprentice electrician was brought in having been electrocuted whilst working under the nearby Denhard's bread factory.  On arrival he was in VF, and Ted Watson set about opening his chest to perform direct cardiac compression while my job was to use an 'S' tube for assisted ventilation.  A call went out to Jim Baird who eventually arrived with the defibrillator and successful defibrillation was achieved.  The patient made a full recovery.

 

 

 

 

Once closed chest compression was established for the management of cardiac arrest, several years would pass before additional defibrillators were placed in strategic locations, such as in the Casualty Department.  Until that eventuated, if a VF cardiac arrest occurred in the hospital and CPR commenced, a call to Jim Baird for defibrillation was made.  Jim made himself available for this on a 24-hour basis, and gained approval from the Traffic Authority to place a flashing green light on his Jaguar and speed after hours to the hospital, sometimes with a traffic cop trailing behind!

 

 

 

The development of machines that delivered a DC shock occurred in 1959 (Bernard Lown) and the first one of these devices, made by American Optical, arrived in Wellington in 1965 when I was cardiology registrar.
  see left
A big advance here was that synchronised DC shocks could be delivered and thus began the application of 'Cardioversion' for elective reversion of atrial fibrillation or flutter.

 

An AO defibrillator was installed in the new cardiac catheter lab which opened in the Seddon Block in 1966.

 

 

 

 

 

 

 

 

 

 

 

 

One of the early crash carts in use was a classic example of number 8 wire DIY.  Don McCallum combined part of the original AO cardioverter/defibrillator along with one of the original Sanborn Viso Cardiette ECG machines in a mobile trolley equipped also with resuscitation gear.

 

 

 

 

 

 

 

 

 

 

 

The AO defibrillator remained in the Cath Lab until 1977 when it was replaced with one from Hewlett Packard.

 

 

 

 

 

 

A similar HP defibrillator was installed in the CCU in the Seddon Block.

In the 1980s, the CCU's HP defibrillator was replaced with the first of a series of LifePacks - initially version 3.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

By the 1980s, there was placement of defibrillators at multiple locations throughout the hospital.   Apart from in theatres, the cardiac catheter lab, ICU, CCU, NNU and the Emergency Department, defibrillators were also located in general ward blocks, ensuring less delay when the need arose.

For some years at least, the popular choice was the LifePack series, such as the LifePack4 seen here.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Last updated 8 October 2021.