Utilization of implantable defibrillators in Africa.

Sub-Saharan Africa is dominated by diseases of poverty. HIV/AIDS affects 28.5 out of a total of 600 million in the region. South Africa is the only country in sub-Saharan Africa in which implantable cardiovertor defibrillators (ICDs) are implanted (0.8/million in 2001). Only 3 of the 35 new ICDs were implanted in state-funded public hospitals. The pacemaker implantation rate for South Africa was 41/million in 2001. Approximately 20% of the population consume 56% of the health care expenditure, mainly funded by Medical Insurance. A tax-funded state health care system serves the rest of the population, but is concentrated on improving sanitation and primary health care. Diversion of funds from academic tertiary hospitals has reduced specialised services, particularly cardiology and cardiac surgery, and has resulted in an exodus of skilled personnel to the private sector. In the rest of sub-Saharan Africa, tertiary health care is mainly privately funded. Cardiology and cardiac surgery is not widely available. Many countries are crippled by debt and chronic local conflicts. Only one state hospital (Groote Schuur, Cape Town) provides an electrophysiology (EP) service including catheter ablation and ICD implantation, and training in EP, by two electrophysiologists. EP services are available privately in 3 centres. No EP service exists in the rest of sub-Saharan Africa.

1998 survey of cardiac pacing in South Africa--report of the working group on registries of the cardiac arrhythmia society of South Africa (CASSA).

BACKGROUND: Permanent pacemakers provide effective relief of symptoms and are life-saving in patients with symptomatic heart block. Since pacemakers are only implanted by cardiologists or cardiothoracic surgeons in tertiary hospitals, the rates of pacemaker implantation provide a readily auditable measure of tertiary health care. METHODS: A survey was conducted of pacemaker implantation in South Africa in 1998, using questionnaires completed by implanters and information on the total number of pacemakers sold during the period, supplied by pacemaker distributors. RESULTS: A total of 1,643 new pacemakers were implanted in 1998 by 112 doctors working in 31 institutions (9 public and 22 private). The annual implant rate per million population was 39, compared with 31/million in 1995, an increase of 25.8%. Public hospitals accounted for 31.7% of primary pacemaker implants in 1998 as opposed to 37% in 1995. Practice in the public sector differed from that in the private sector in that atrioventricular (AV) block was the major indication for pacing in 75.3% versus 45.3%, whereas sinus node dysfunction accounted for 34.9% of private patients, as opposed to 16.2% of public hospital patients. Simple VVI single-chamber pacemakers accounted for 49.5% of public hospital implants versus only 9.6% in private patients. The reverse was true for dual-chamber implants (12.1% v. 42.3%). Severe cost constraints in the public sector have resulted in increasing use of cheaper single-chamber pacemakers for more stringent indications (predominantly AV block). The overall implant rate remains low compared with a median of 283/million in Europe. Large discrepancies persist between race groups (232/million whites, as opposed to 8.8/million blacks) and regions (89.3/million in the Western Cape versus 10.8/million in the four provinces without pacemaker implanters). CONCLUSION: It is likely that socio-economic factors play a major role in the unequal distribution of this highly effective treatment for potentially lethal bradyarrhythmias. The changing trends in pacemaker implantations indicate a shift of tertiary health care resources from the public to the private sectors.

Supraventricular tachycardia during spinal anaesthesia for caesarean section.

A woman of 40 weeks' gestation, who was apparently previously healthy, required emergency caesarean section after a failed vacuum delivery. While under spinal anaesthesia she developed a supraventricular tachycardia of unknown origin. Intravenous verapamil resulted in a conversion to sinus rhythm. Further investigations confirmed Wolff-Parkinson-White syndrome, for which she required ablation therapy. Appropriate methods of cardioversion in this clinical setting are discussed.

Long-term survival after permanent pacemaker implantation in young adults: 30 year experience.

The goal of the present study was to determine the etiology of conduction disease and long-term outcome for young adults who undergo permanent pacemaker implantation. Permanent pacing was performed in 232 patients aged 21-50 years, 135 males and 97 females, from 1965 through 1995. One hundred and twenty-six subjects (54%) had evidence of structural heart disease, while idiopathic conduction disease accounted for 46%. About half (54%) of 106 patients with structural heart disease had surgically induced heart block. Pacing mode at primary implantation was single chamber in 65% and dual chamber in 35%. Follow-up ranged from 12-387 months, with a mean of 104-months. At the last follow-up, 133 of 232 patients (57%) were alive, 40 (17%) had died, 30 (13%) were lost to follow-up, 26 (11%) were transferred elsewhere, and 3 (1%) explanted. Patients with sick sinus syndrome had similar outcomes to those with AV block. There was a sharp decline in survival during the first six months; 7.5% of the sample died within the first year following their first pacemaker operation. After the first year, the decline in survival slowed and 70% of the patients could be expected to survive beyond 20 years. The overall survival of young patients without structural heart disease who received a permanent pacemaker was comparable to an age- and sex-matched control population, while patients with structural heart disease performed significantly worse than the control population.

VDD pacing in persistent left superior vena cava.

Although persistent left superior vena cava (PLSVC) is the most common major venous anomaly of the heart, associated absence of the right superior vena cava with normal visceral situs is exceedingly rare. Such a patient presented with complete heart block requiring permanent pacing. This was achieved successful using a single lead VDD system via the PLSVC with atrial sensing in the coronary sinus.

Selective catheter ablation of the slow atrioventricular nodal pathway for atrial fibrillation.

The slow AV nodal pathway was ablated selectively in a 62-year-old man with uncontrolled rapid atrial fibrillation. This resulted in a much slower ventricular response without the need for permanent pacing. The pathophysiology is discussed.

The haemodynamic correlations of the cardiopulmonary flow index, a relatively non-invasive technique for diagnosis of myocardial pump insufficiency.

The cardiopulmonary flow index (CPFI) is the ratio of cardiopulmonary blood volume to stroke volume. OBJECTIVE. To compare the CPFI derived from a first-pass radiocardiogram and electrocardiogram with the usual haemodynamic measurements obtained by bedside catheterisation. DESIGN. Sixty-one patients in a coronary care unit who had flow-directed pulmonary artery catheterisation for clinical indications had a CPFI recorded together with the usual haemodynamic measurements and calculations. RESULTS. In patients with myocardial pump failure without significant pulmonary disease, linear regression analysis indicated that the best fit for the CPFI could be obtained with a model that used the inverse of stroke index and pulmonary capillary wedge pressure as independent variables. Ninety-six per cent of the variation in CPFI can be explained by variations in pulmonary capillary wedge pressure and stroke index. The CPFI correlated less well with these variables in patients with concomitant lung disease. CONCLUSION. The CPFI is a potentially useful and relatively non-invasive index of haemodynamic function in acutely ill patients without significant pulmonary disease.

Cardiovascular collapse due to intravenous verapamil in two patients with persistent atrial tachycardia.

Intravenous verapamil was given to two haemodynamically stable patients with persistent atrial tachycardia, resulting in circulatory arrest requiring CPR in one and collapse with unrecordable blood pressure in the other. Both responded to resuscitation and tachycardia was subsequently controlled with propranolol in one and sotalol in the other. Factors contributing to the cardiovascular collapse included: (i) left ventricular dysfunction; and (ii) failure to convert the tachycardia to sinus rhythm. It was concluded that verapamil may be dangerous in supraventricular tachycardia not due to atrioventricular (AV) junctional re-entry, despite normal blood pressure and perfusion, particularly if left ventricular dysfunction were present. If the diagnosis of AV junctional re-entry is in doubt, adenosine is preferable as it is less likely to cause haemodynamic collapse and will assist in making the diagnosis.

A prospective study of electrical cardioversion for sustained tachycardias by emergency unit personnel.

Acute symptomatic tachyarrhythmias are commonly seen by emergency unit personnel. Electrical cardioversion is often used at Groote Schuur Hospital to treat such patients because of concerns about the safety and efficacy of intravenous anti-arrhythmic agents. All patients presenting with acute symptomatic tachyarrhythmias who were managed only by the staff of the Emergency Unit were entered into the study to assess the efficacy and safety of direct current (DC) cardioversion. Those with sinus tachycardia or atrial fibrillation of more than 24 hours' duration were excluded. Staff, on joining the unit, were instructed in the use and technique of DC cardioversion, and given simple guidelines for the management of acute tachyarrhythmias. Fifty-three patient events were seen over a period of 16 months: 7 patients had ventricular tachycardia, 21 had atrial flutter, 20 had paroxysmal junctional re-entry tachycardia, 4 had atrial fibrillation and 1 had multifocal atrial tachycardia. Fifty-two were successfully converted to sinus rhythm. One patient with atrial flutter and 9 with paroxysmal junctional re-entry tachycardia reverted after undergoing vagal manoeuvres or receiving intravenous verapamil. Of the remaining 43 patients, 42 (98%) were cardioverted with synchronised DC shock under midazolam sedation (7/7 ventricular tachycardia, 20/20 atrial flutter, 11/11 paroxysmal junctional re-entry tachycardia, 4/4 atrial fibrillation, 0/1 multifocal atrial tachycardia). Four patients had their sedation electively reversed with flumazenil. No complications occurred. DC cardioversion was only considered inappropriate in the 1 patient with multifocal atrial tachycardia. This study shows that if simple guidelines are followed, non-cardiologist junior medical personnel can safely and effectively manage sustained, acute, symptomatic tachyarrhythmias by employing DC cardioversion as and when appropriate.

Pacemaker induced superior vena cava obstruction: management by spiral vein graft.

A 35-year-old male developed superior vena cava (SVC) obstruction due to multiple retained pacemaker leads. This caused cyanosis and suffusion of the head and neck during arm exercise, with desaturation from 99%-90% demonstrated by ear oximetry. The SVC was bypassed using a spiral vein graft because of worsening symptoms. Dramatic improvement resulted, with desaturation no longer demonstrable.

Surgical cure of the Wolff-Parkinson-White syndrome--a comparison of two techniques.

Curative arrhythmia surgery for patients with symptomatic Wolff-Parkinson-White syndrome (WPW) was first performed in South Africa in November 1987. Pre-operatively all patients were symptomatic despite medical therapy, and 32% were assessed as being at risk for sudden death. The first 9 patients (November 1987 to December 1989) underwent either epicardial or localised endocardial surgical dissections, and a cure was obtained in 66%. Aberrant atrioventricular conduction recurred in 2 patients, 3 degrees atrioventricular heart block occurred in 2 patients, and there was 1 postoperative death in a patient who had undergone simultaneous coronary artery bypass grafting. In contrast, a standardised endocardial technique was used in the subsequent 10 patients. Surgical cure was obtained in all 10 patients (P < 0.01). However, 1 patient required reoperation 24 hours after the first procedure because of early postoperative recurrence due to initial incorrect pathway localisation. This was successful. There were no deaths, and no patient developed atrioventricular heart block. In view of the excellent surgical results, arrhythmia surgery should be considered in select WPW patients who either have refractory symptoms or are at risk for sudden death. Furthermore, this reliable surgical technique provides an essential back-up should alternative interventional procedures such as percutaneous radiofrequency ablation fail.

Normal left ventricular function does not protect against propafenone-induced incessant ventricular tachycardia.

Propafenone is a class Ic anti-arrhythmic agent with mild beta-blocking properties which has recently become available in South Africa. We have used the drug in 3 patients with sustained monomorphic ventricular tachycardia not due to ischaemic heart disease. All had normal left ventricular function; 1 had Wegener's granulomatosis and 2 had arrhythmogenic right ventricular dysplasia. In the latter 2, propafenone provoked incessant monomorphic ventricular tachycardia which persisted for more than 24 hours despite repeated efforts at termination. The morphology was similar to the patients' spontaneous ventricular tachycardia, but the rate was slower and the QRS complexes broader, consistent with propafenone's marked ability to slow intraventricular conduction. It is postulated that incessant tachycardia results from perpetuation of re-entry due to marked conduction slowing produced by the drug. Previous reports have suggested that this is most likely to occur in patients with poor left ventricular function, but our experience indicates that those with normal left ventricular function are also at risk, particularly if the substrate for re-entry is present. Propafenone, like all other powerful anti-arrhythmic agents, may provoke life-threatening arrhythmias and should be used with great caution after due consideration of the indications, even in patients with normal left ventricular function.