The Australian and New Zealand Cardiac Implantable Electronic Device Survey, Calendar Year 2021: 50-Year Anniversary.

Background: A cardiac implantable electronic device (CIED) survey was undertaken in Australia and New Zealand for calendar year 2021. The survey involved pacemakers (PMs) and implantable cardioverter-defibrillators (ICDs). The survey was conducted on the 50 anniversary of the first survey for both Australia and New Zealand in 1972; that initial survey being conducted by two of the current authors.

The Cardiac Pacemaker Clinic: Memories From a Bygone Era.

In 1963, soon after the first ventricular pacemakers were implanted at the Royal Melbourne Hospital, attempts were made to identify impending pacing failure, thus preventing sudden death in these very vulnerable patients. By 1970, patient numbers had increased, a formal regular pacemaker clinic was established, and guidelines and protocols developed. The clinic was staffed by a physician, a biomedical engineer and cardiac technicians.

The Australian history of cardiac pacing: memories from a bygone era.

Although Dr Albert Hyman in New York is believed to have built the first cardiac pacemaker in 1932, he acknowledges Dr Mark Lidwell in Sydney, Australia as having not only built a pacemaker, but also successfully used it to resuscitate a newborn infant in or before 1929. Fully implantable pacemakers, however, were not possible until 1958, following the development of the silicon transistor. Within three years of that first implant, a pulse generator attached to epicardial leads was implanted at the Royal Melbourne Hospital.

Cardiac pacing: memories of a bygone era.

The first cardiac pacemaker implants occurred in the late 1950s and involved insertion of epicardial or epimyocardial leads and abdominal pulse generators. By the mid 1960s, cardiologists were making attempts to insert transvenous leads into the right ventricle. These early unipolar leads had large, polished, high polarization electrodes, no fixation device, and no lumen in which to place a stylet for lead positioning.

Effect of pravastatin compared with placebo initiated within 24 hours of onset of acute myocardial infarction or unstable angina: the Pravastatin in Acute Coronary Treatment (PACT) trial.

Background: The efficacy of statin drugs after an acute coronary event is now well established, but the evidence for statin use in the early treatment of acute coronary events remains unclear.

Methods: We tested the effects of administering pravastatin within 24 hours of the onset of symptoms in patients with unstable angina, non-ST-segment elevation myocardial infarction, or ST-segment elevation myocardial infarction. Patient recruitment of 10,000 with 1200 end points was planned, but the trial was stopped early.

Low-level lead exposure and children's cognitive function in the preschool years.

In a cohort of 170 middle and upper-middle class children participating in a prospective study of child development and low-level lead exposure, higher blood lead levels at age 24 months were associated with lower scores at age 57 months on the McCarthy Scales of Children's Abilities. The mean blood lead level at age 24 months was 6.8 micrograms/dL (SD = 6.

Antecedents and correlates of improved cognitive performance in children exposed in utero to low levels of lead.

Up to 2 years of age, children with umbilical cord blood lead levels of 10 to 25 micrograms/dL achieve significantly lower scores on tests of cognitive development than do children with lower prenatal exposures. By age 5 years, however, they appear to have recovered from, or at least compensated for, this early insult. Change in performance between 24 and 57 months of age was examined in relation to level of postnatal lead exposure and various sociodemographic factors.

Infantile colic and transient developmental lag in the first year of life.

This study investigates the impact of infantile colic on subsequent development. Infants with a history of colic scored significantly lower on the Mental and Psychomotor scales of the Bayley Scales of Infant Development at age 6 months but there was no significant effect of colic on test performance at later ages. The data suggest that this temporary delay in development may be due in part to less favorable patterns of caregiver-infant interaction as a result of the history of colic.

Dexamethasone-induced increase in in vitro clonogenicity of human neoplasms.

The addition of the corticosteroid hormone, dexamethasone, to the culture medium results in a significant enhancement of tumor colony growth in the human tumor clonogenic assay. Taking 20 as the mean minimum number of colonies per dish that allows evaluation of 122 cultured tumors, 67 were fully evaluable in the presence of dexamethasone whereas only 34 were evaluable when it was omitted. The addition of dexamethasone significantly (P less than .

Significance of glucocorticoid receptors and responses in leukaemia.

Glucocorticoid receptor levels and cellular responses to glucocorticoid treatment in vitro were evaluated for the malignant cells from patients with leukaemia. Cells from all cases of lymphoid and myeloid leukaemia contained glucocorticoid receptors; receptor levels and the extent of in vitro responses appeared to depend primarily on cell type and differentiation status. For acute lymphoblastic leukaemia (ALL), high receptor levels were associated with the common ALL phenotype, intermediate levels with null (unclassified) ALL and low levels with T-ALL.

In vivo stimulation of murine granulopoiesis by human urinary extract from patients with aplastic anemia.

Significant in vivo stimulation of granulopoiesis was induced in mice by the administration of an extract from the urine of patients with aplastic anemia (AA). Sialic acid has been identified as an important molecular component for the in vivo biological activity of this granulopoietic factor, "granulopoietin," which is distinct and different from endotoxin. Urine from patients with AA was successively fractionated by Sephadex G-50 and DEAE-cellulose chromatography.

The antiarrhythmic effect of intravenous disopyramide in an open study.

The antiarrhythmic effect of intravenous disopyramide phosphate was assessed in a multicentre open study of 141 patients admitted to coronary care units. Disopyramide was administered in a bolus dose of 2 mg/kg over 10 min with an optional second bolus of 1 mg/kg and infusion of 0.4 mg/kg hour.

Subendocardial myocardial infarction.

Sixty-one consecutive patients with acute subendocardial myocardial infarction (SEAMI) and 223 consecutive patients with transmural infarction (TMI) seen in a coronary care unit were followed for one year. All patients were less than 70 years of age. The patients with SEAMI had a higher frequency of previous infarction (34% vs 21%, p less than 0.

Recent concepts in the management of ischaemic cardiac syndromes.

Ischaemic heart disease is the most important cause of death in our society. Knowledge of the natural history of the various ischaemic syndromes leads to better management, with emphasis on prevention of cardiac necrosis rather than management of its sequelae. This article is from the Department of Cardiology, Royal Melbourne Hospital.

The value of postcardiac infarction exercise stress testing: identification of a group at high risk.

We prospectively selected 154 patients who had survived acute myocardial infarction with electrical and/or mechanical complications to undergo an exercise stress test, four to six weeks after discharge from the Coronary Care Unit, Royal Melbourne Hospital. The patients exercised on a bicycle ergometer until they were unable to continue or had reached 70% of their predicted maximum heart rate for their age. Eighteen (11.

Coronary artery graft surgery.

The last decade has seen significant technical advances in equipment for the procedure of, and the surgeon's operating skill in coronary artery by pass surgery. Such surgery is indicated when, despite medical treatment, angina is disabling; although evidence is increasing that patients whose pain is controlled should be considered for surgery. Late operations are more complex and expensive, and patients are exposed to a higher risk of sudden death in the intervening period.

Haemodynamic response to ACTH administration in essential hypertension.

1. The haemodynamic and volume response to ACTH administration was investigated in six patients with mild, untreated essential hypertension and two patients with Addison's disease on maintenance steroids. Blood pressure, heart rate and weight were recorded daily.

The malfunctioning pacemaker system. Part I.

The success of an implanted cardiac pacemaker is dependent upon the establishment of a harmonious relationship between the artificial pacemaker and the human receiver. Failure of a pacemaker system may arise from an electronic or mechanical defect within the pacemaker, a physiologic problem, or from a poor relationship between the normal function of both. Such malfunctions may necessitate the repair, replacement, or repositioning of a pacemaker component or removal of a source of external interference.