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D L Jardine

Publications and source records attributed to D L Jardine.

18 recordsLinked to original sources
PubMed2003

Respiratory failure secondary to diabetic neuropathy affecting the phrenic nerve.

We report a patient with Type 2 diabetes mellitus complicated by neuropathy affecting the phrenic nerves, resulting in fatal respiratory failure. Diabetic mononeuropathy is common and usually recovers spontaneously, but bilateral phrenic nerve involvement appears to be uncommon and difficult to treat. The pathology of diabetic mononeuropathy is not well understood and we believe this to be the first histological report of a phrenic nerve biopsy in this condition.

Aged↗
PubMed2002

Decrease in cardiac output and muscle sympathetic activity during vasovagal syncope.

The importance of cardiac output (CO) to blood pressure level during vasovagal syncope is unknown. We measured thermodilution CO, mean blood pressure (MBP), and leg muscle mean sympathetic nerve activity (MSNA) each minute during 60 degrees head-up tilt in 26 patients with recurrent syncope. Eight patients tolerated tilt (TT) for 45 min (mean age 60 +/- 5 yr) and 15 patients developed syncope during tilt (TS) (mean age 58 +/- 4 yr, mean tilt time 15.4 +/- 2 min). In TT patients, CO decreased during the first minute of tilt (from 3.2 +/- 0.2 to 2.5 +/- 0.3 l x min(-1) x m(-2), P = 0.001) and thereafter remained stable between 2.5 +/- 0.3 (P = 0.001) and 2.4 +/- 0.2 l x min(-1) x m(-2) (P = 0.004) at 5 and 45 min, respectively. In TS patients, CO decreased during the first minute (from 3.3 +/- 0.2 to 2.7 +/- 0.1 l x min(-1) x m(-2), P = 0.02) and was stable until 7 min before syncope, falling to 2.0 +/- 0.2 at syncope (P = 0.001). Regression slopes for CO versus time during tilt were -0.01 min(-1) in TT versus -0.1 l x min(-1) x m(-2) x min(-1) in TS (P = 0.001). However, MBP was more closely correlated to total peripheral resistance (R = 0.56, P = 0.001) and MSNA (R = 0.58, P = 0.001) than CO (R = 0.32, P = 0.001). In vasovagal reactions, a progressive decline in CO may contribute to hypotension some minutes before syncope occurs.

Adult↗
PubMed2001

A Comparative Study of Blood Pressure Control with Short In-Center versus Long Home Hemodialysis.

We conducted a randomized crossover trial to establish, within patients, whether long-slow hemodialysis (HD) was associated with better blood pressure (BP) control than standard HD. Nine home HD patients, not on antihypertensive drugs, were dialyzed to the same eKt/V(urea) and target weights for 6-8 h (LD) at home and for 3.5-4.5 h (SD) in the dialysis center 3 times weekly in randomized sequence, with each phase lasting 8 weeks. Ambulatory BP, bioimpedance, neurohormones and autonomic function were measured in each phase. Pre- and postdialysis systolic, ambulatory systolic and diastolic BP were all higher with SD than with LD and intradialysis hypotension was more common. Weight, ECF volume and neurohormones did not differ between treatments. Muscle sympathetic activity was increased in both phases and cardiac sympathetic activity tended higher during SD. These findings suggest that additional factors to ECF volume may contribute to the superior BP control produced by long-slow HD.

Adult↗
PubMed2000

Baroreceptor denervation presenting as part of a vagal mononeuropathy.

A 48-year-old woman presented with a history of progressive cough, dysphonia, dysphagia, and postural symptoms. Subsequent neurological investigations were consistent with a bilateral vagal mononeuropathy, and neurosarcoidosis was diagnosed after scalene node biopsy. Autonomic investigations including microneurography, neurohormones, and heart rate variability demonstrated arterial and cardiopulmonary baroreflex failure. In addition, parasympathetic control of heart rate was absent and consistent with a bilateral, nonselective lesion in the proximal vagus.

Arginine Vasopressin↗
PubMed2000

Brain stem stroke causing baroreflex failure and paroxysmal hypertension.

BACKGROUND: Paroxysmal neurogenic hypertension has been associated with a variety of diseases affecting the brain stem but has only rarely been reported after brain stem stroke. The mechanism is thought to involve increased sympathetic activity and baroreflex dysfunction. We undertook microneurographic recordings of muscle sympathetic nerve activity (MNSA) during beat-to-beat blood pressure (BP) monitoring to investigate this hypothesis. CASE DESCRIPTION: We investigated a 75-year-old woman who developed paroxysmal hypertension (BP 220/110 mm Hg) after a large left-sided medullary infarct. The paroxysms were triggered by changes in posture and were accompanied by tachycardia, diaphoresis, and headache. Serum catecholamines were substantially increased (norepinephrine level, 23.9 nmol/L 9 days after stroke; normal level, <3.8 nmol/L), and heart rate variability, measured by spectral analysis, was decreased in both low- and high-frequency domains (0.04 and 0.06 ms(2), respectively; normal level, 0.14+/-0.02 ms(2)). MNSA was increased in frequency (61 bursts per minute; normal level, 34+/-18 bursts per minute), and the burst amplitude was not inversely related to diastolic BP. BP and MNSA responses to cold pressor and isometric handgrip stimuli were intact. CONCLUSIONS: Extensive unilateral infarction of the brain stem in the region of the nucleus tractus solitarius may result in partial baroreflex dysfunction, increased sympathetic activity, and neurogenic paroxysmal hypertension.

Aged↗
PubMed1998

Autonomic control of vasovagal syncope.

In the pathophysiological study of vasovagal syncope, the nature of the interaction between baroreceptor sensitivity (BS), sympathetic withdrawal, and parasympathetic activity has yet to be ascertained. Altered BS may predispose toward abnormal sympathetic and parasympathetic responses to orthostasis, causing hypotension that may progress to syncope if there is sympathetic withdrawal. To examine this hypothesis, we monitored blood pressure (BP), heart rate (HR), BS, forearm blood flow, and muscle nerve sympathetic activity (MNSA) continuously in 18 vasovagal patients during 60 degrees head-up tilt, syncope, and recovery. Results were compared with those of 17 patients who were able to tolerate tilt for 45 min. During early tilt, BP was maintained in both groups by an increase in HR and MNSA from baseline (P < 0.01), but BS decreased more in the syncopal group (P < 0.05). At the start of presyncope (mean 2.7 +/- 0.2 min before syncope and 15.2 +/- 12 min after tilt), when BP fell, HR and sympathetic activity remained increased from baseline (P < 0.01). Thereafter, BP and HR correlated directly with sympathetic activity and regressed in linear fashion until syncope (P < 0.001), whereas BS increased to baseline. At syncope, BP, HR, and sympathetic activity fell below baseline (P < 0.01, P < 0.05, and P < 0.01, respectively), but BS did not increase. During recovery, sympathetic activity increased to baseline and BS increased (P < 0.05), whereas HR and BP remained low (P < 0.01 and P < 0.05, respectively). The mechanism for the initiation of hypotension during presyncope remains unknown, but BS may contribute. Vasodilatation and bradycardia during presyncope appear to be more closely related to withdrawal of sympathetic activity than to increased parasympathetic cardiac activity.

Adult↗
PubMed1997

Neurohormonal response to head-up tilt and its role in vasovagal syncope.

In a controlled study, 26 patients with a history of recurrent syncope were found to have increased arginine vasopressin, corticotrophin, and atrial natriuretic factor levels after 5 minutes of 60 degrees head-up tilt, long before they became hypotensive. The exaggerated neurohormonal response in these patients may indicate a greater sensitivity to central hypovolemia which may predispose to vasovagal syncope, mediated by the vasodilatory effects of atrial natriuretic factor or the sensitization of mechanoreceptors by arginine vasopressin.

Adrenocorticotropic Hormone↗
PubMed1997

Right atrial myxoma mistaken for recurrent pulmonary thromboembolism.

A 69 year old man was admitted for investigation of right sided pleuritic chest pain and dyspnoea, both of which began suddenly four days before admission. Acute pulmonary embolism was diagnosed. Six months after discharge while on warfarin he died. Necropsy found a 50 mm diameter myxoid tumour arising on the right atrial side of the interatrial septum. This lesion may have been discovered earlier by echocardiography although there were no clear indications for this investigation. Presentation was that of recurrent pulmonary embolism with no obvious source or cause of thrombosis. Patients who are thought to have idiopathic pulmonary embolism should undergo early echocardiography to exclude the rare but treatable diseases of the right heart that may be responsible.

Aged↗
PubMed1996

Autonomic control of asystolic vasovagal syncope.

A 30 year old woman with a lifelong history of severe, recurrent, vasovagal syncope became asystolic for 30 seconds after 37 minutes of 60 degrees head-up tilt. During early tilt, sympathetic activity, heart rate, left ventricular contractility, and cardiac output increased. Mean blood pressure was initially maintained. Presyncope was associated with maximal contractility and bradycardia despite sustained sympathetic activity. Subsequently, asystole occurred associated with complete withdrawal of muscle nerve sympathetic activity. In asystolic vasovagal reactions, presyncope may be triggered by increased left ventricular contractility and is associated with increased levels of parasympathetic and sympathetic activity. Asystole and peripheral vasodilatation may be caused by sudden and complete withdrawal of the increased sympathetic activity.

Adult↗
PubMed1994

Primary biliary cirrhosis presenting with granulomatous skin lesions.

A case is described of primary biliary cirrhosis in a 59 year old woman who initially presented with a rash over her lower legs 18 months before diagnosis. Skin biopsy examination showed non-caseating granulomas of the sarcoid type. It is believed that this is the first reported case of primary biliary cirrhosis presenting with a granulomatous rash.

Female↗
PubMed1993

Renal artery stenosis as a cause of heavy albuminuria.

We report three cases of heavy albuminuria occurring in hypertensive patients with unilateral or bilateral renal artery stenosis. In two of the patients the albuminuria and hypertension were corrected by removing the ischaemic kidney. The mechanism of the albuminuria, particularly in atheromatous renal artery stenosis, is probably multifactorial.

Adult↗
PubMed1991

Epstein-Barr virus infection acquired from a cadaveric renal transplant.

A 42-year-old man, seronegative for Epstein-Barr virus (EBV), received a cadaveric renal transplant. Serology from the 27-year-old male donor indicated an active EBV infection. Following treatment for acute rejection with OKT3 the recipient developed a severe systemic illness. Clinical features strongly suggested an acute EBV infection and serology showed seroconversion for EBV. The patient died and autopsy histology revealed widespread polymorphic lymphocyte infiltration in lymph nodes and solid organs. To our knowledge this is the first report of a kidney being transplanted from a donor who was subsequently shown to have had EBV infection at the time of organ retrieval. The EBV status of an organ donor should be considered more frequently.

Adult↗
PubMedDate not supplied

Small bowel ischaemia in Fabry's disease.

A patient with previously diagnosed Fabry's disease and a long history of post-prandial abdominal pain died following small bowel infarction. Post-mortem demonstrated Fabry's type deposits in the small vessels and nerves supplying the bowel but in addition, a localized atheromatous stenosis of the superior mesenteric artery. In retrospect, his terminal illness and possibly his chronic symptoms were related to the latter finding. Angioplasty to the superior mesenteric artery may have been of benefit. Mesenteric angiography should be considered in patients with chronic post-prandial pain because large vessel disease may coexist with other a priori pathologies and is imminently treatable.

Arteriosclerosis↗