Dilated cardiomyopathy in Doberman Pinschers: Survival, Causes of Death and a Pedigree Review in a Related Line.

OBJECTIVE: To analyze clinical, electrocardiographic and echocardiographic characteristics, survival, cause of death and possible modes of inheritance of dilated cardiomyopathy (DCM) in Doberman pinschers (DP) and to compare the occurrence and survival with dogs of other breeds. Dogs - Two cohorts of dogs were studied: 1. A consecutive series of 52 dogs of different breeds with DCM were included, 21 were Doberman pinschers and 31 dogs belonged to other breeds: 2. 28 asymptomatic Doberman pinschers, who were screened for DCM. Methods - Medical records of dogs with DCM were reviewed. Physical, electrocardiographic and echocardiographic examinations were performed on asymptomatic Doberman pinschers. Their pedigrees were reviewed. RESULTS: Doberman pinschers survived on average 52 days (range <1-180), while dogs of other breeds survived significantly longer, i.e. 240 days (<1-1230). Survival of Doberman pinschers in congestive heart failure (mean 62, range <1-180) was not different from survival of Doberman pinschers with sudden death (mean 33, range <1-105). High prevalence, short survival time and the clinical course of DCM in Doberman pinschers showed similarities to previous studies. Twenty-one percent of asymptomatic Doberman pinschers had increased left ventricular end-systolic diameter and 14% developed DCM within a year. A line of Doberman pinschers with multiple members affected with DCM was identified by the review of their pedigrees. Exact mode of inheritance could not be established. CONCLUSIONS: The prognosis of Doberman pinschers with DCM is poor. Further molecular genetic studies, which would enable detection and exclusion of disease carriers from the breeding, are necessary.

Gender differences in athlete's heart: association with 24-h blood pressure. A study of pairs in sport dancing.

BACKGROUND: Long term athletic training is associated with an increase in left ventricular diastolic cavity dimensions, wall thickness, and mass. These changes are described as the "athlete's heart". In comparison to men, athletic training in women athletes is not a stimulus for substantial increase in left ventricular wall thickness. Although many variables are related to these gender differences in cardiac morphology, some factors such as 24-h blood pressure and the level of training have not been studied yet. Therefore pairs in sport dancing, in which the level of training of both partners is the same, were chosen as models in order to evaluate whether 24-h blood pressure contributes to sex-related differences in an athlete's heart. METHODS: Fifteen pairs in the national sport dancing team and 30 control subjects (15 males, 15 females) were studied. In all subjects casual and 24-h ambulatory blood pressures, echocardiography, and maximal stress testing were performed. RESULTS: Female in comparison to male dancers had significantly lower M-mode (P<0.004) and 2-D left ventricular mass index (P<0.001), 24-h systolic blood pressure (P<0.003), day systolic blood pressure (P<0.002), casual systolic blood pressure (P<0.025), and achieved significantly lower peak systolic blood pressure at stress testing (P<0.004). Multiple stepwise regression analysis showed that the best predictors of 2-D left ventricular mass index are maximal work load and peak exercise systolic blood pressure, 24-h systolic blood pressure, day, and casual systolic blood pressure. CONCLUSIONS: Lower left ventricular mass index in female dancers can be partly explained by lower systolic blood pressures during 24-h and at exercise.

Ventricular ectopic activity, left ventricular mass, hyperinsulinemia, and intracellular magnesium in normotensive patients with obesity.

Insulin resistance, a well-known feature of obesity, is associated with several pathological changes, which are potentially arrhythmogenic. Ventricular ectopic activity in normotensive obese patients has not been studied in detail. Therefore the authors designed a study to investigate potential relationships among ventricular ectopic activity, left ventricular mass, hyperinsulinemia, and intracellular magnesium concentration in obese patients. Thirty-two obese patients and 32 nonobese control subjects, who were referred to outpatient department because of ventricular ectopy, participated in the study. The groups were matched for age and gender. All had normal glucose tolerance. All subjects underwent a 75-g glucose tolerance test, and blood samples were obtained at 30, 60, and 120 minutes thereafter for determination of glucose and insulin concentrations. Echocardiography was performed and left ventricular mass index was calculated. The number of ventricular ectopic beats per hour (VEB/hour) was recorded by 24-hour ECG Holter monitoring. Plasma and erythrocyte magnesium concentrations were determined by atomic absorption spectrophotometer. Obese patients had higher body weight, body mass index, heart rate, and left ventricular mass index. Obese subjects had higher fasting insulin as well as insulin/glucose ratio and broader area under the curve of insulin (AUC-I) compared to nonobese subjects. Insulin sensitivity appeared to be lower in the obese group. Holter monitoring showed more VEB/hour in the obese group. Magnesium concentration in serum and in erythrocytes was lower in obese persons. In the obese group a positive correlation was found between left ventricular mass index and fasting insulin (r=0.345, p=0.027), insulin/glucose index (r=0.351, p=0.049), and AUC-I (r=0.405, p=0.011). The number of VEB/hour in obese patients was in positive correlation with age (r=0.681, p<0.001), left ventricular mass index (r=0.542, p=0.001), fasting insulin (r=0.380, p=0.016), and AUC-I (r=0.493, p=0.002) and in negative correlation with magnesium concentration in erythrocytes (r=-0.457, p=0.004). Multiple regression analysis showed that age and AUC-I are the only determinants of VEB/hour and together explained 56% of the variability in the obese subjects. It appears that in obese normotensive subjects, ventricular ectopic beats are related to age, insulin resistance, left ventricular mass index, and decreased intracellular magnesium content.

Are insulin metabolism and night-time blood pressure related to left ventricular hypertrophy?

Essential hypertensives in whom blood pressure does not fall during sleep (non-dippers) are thought to be at greater risk of cardiovascular morbidity. Insulin resistance is also suggested to be a risk factor for cardiovascular morbidity. The purpose of the present study was to evaluate the relationship of insulin metabolism to left ventricular hypertrophy in dippers and non-dippers. Thirty male, non-diabetic out-patients with newly diagnosed arterial hypertension were included in the study: 21 dippers (mean age 45+/-13 years; body mass index 28.2+/-4.0 kg/m2) and nine non-dippers (mean age 48+/-10 years, body mass index 28.6+/-3.9 kg/m2). Patients were subdivided into dippers and non-dippers on the basis of 24-h ambulatory blood pressure monitoring. Insulin and glucose responses to an oral glucose load have been evaluated. C-peptide levels were determined. Left ventricular mass was assessed by echocardiography. Non-dippers had significantly higher mean night-time systolic (non-dippers: 148+/-9; dippers: 123+/-16 mmHg; P<0.001), diastolic blood pressure (non-dippers: 90+/-8; dippers: 77+/-8 mmHg; P<0.001) and non-significantly higher left ventricular mass (279+/-92 g) and left ventricular mass index (135+/-46 g/m2). No significant difference was found between C-peptide, insulin, glucose levels and incremental areas between the two groups. Night-time blood pressure, insulin, C-peptide and glucose did not correlate with left ventricular mass in non-dippers. Dippers showed a positive correlation between fasting C-peptide and left ventricular mass (r=0.48, P=0.02) and between glucose and left ventricular mass (r=0.42, P=0.05). Our data indicate that night-time blood pressure and insulin are not related to left ventricular hypertrophy in patients with essential hypertension.

Diastolic function and insulin resistance in essential hypertension.

We studied the relationship of insulin metabolism to diastolic function in 41 hypertensive patients and 24 healthy subjects. They underwent a 75-g oral glucose tolerance test. Integrated response of insulin to the glucose load was calculated as the area under the curve of insulin (AUC-I) and glucose (AUC-G). The ratio AUC-I/AUC-G was taken as an index of insulin resistance. Echocardiographic examination was performed to measure left ventricular mass. We used pulsed Doppler technique to assess the ratio of early to late transmitral peak velocity (E/A). The hypertensives had higher fasting insulin concentrations, insulin levels at 60 min and at 120 min after oral glucose load. They had higher AUC-I and higher index of insulin resistance compared to normotensives. Patients with hypertension had a lower E/A ratio in comparison to normotensive volunteers. In all subjects, the E/A ratio was negatively correlated with fasting insulin and insulin concentrations at 30, at 60 and at 120 min, AUC-I and insulin resistance index. Multiple regression analysis was performed to evaluate the above relationships, when the effects of confounding factors such as age, heart rate and systolic blood pressure were taken into account. We found that E/A ratio is negatively correlated to insulin concentrations at 120 min and to AUC-I in hyperinsulinemic subgroup of subjects (fasting insulin> 10). We conclude, that insulin metabolism and E/A ratio, which reflects diastolic function of the left ventricle, are related in hypertension.

Independence of pressure reactivity from pressure levels in Tecumseh, Michigan.

The relation between blood pressure level and reactivity to mental arithmetic and isometric exercise was investigated in 169 men and 120 women (average age, 32.3 years) from the village of Tecumseh, Mich. In the entire population, the correlation between baseline blood pressure and blood pressure response to both stressors was not significant. Blood pressure reactivity to both stressors was not increased in participants with borderline hypertension (one clinic reading of more than 140 mm Hg systolic and/or 90 mm Hg diastolic). When subjects were classified according to blood pressure response (below and above the 80th percentile), the hyperreactors to mental and physical stress had normal baseline blood pressure values. The hyperreactors also had clinic-to-home blood pressure differences similar to those of the rest of the population. Participants who had borderline hypertension at age 32 years had significantly elevated blood pressures at ages 5, 8, 12, 21, and 22 years. Those who were hyperreactors at age 32 years had normal blood pressures as children and young adults. Results of the present study lend no support to an association between higher blood pressures and blood pressure hyperreactivity. Study participants in Tecumseh will be recalled for future examinations. The independence of blood pressure levels from blood pressure reactivity offers a unique opportunity to prospectively evaluate their separate effects on cardiovascular morbidity.

Amyloidosis in saphenous vein aortocoronary bypass grafts.

A patient in whom idiopathic amyloidosis of aortocoronary saphenous vein grafts was found at autopsy two years after myocardial revascularization due to coronary atherosclerosis is reported. Idiopathic generalized immunocyte derived amyloidosis extensively studied at autopsy was obviously present at the time of surgery although it remained unnoticed macroscopically in the inserted graft. It appears that simultaneously with arterialization further deposition and also significant redistribution of amyloid within the walls of the vein grafts additionally took place after their insertion. It seems interesting that in spite of the amyloidosis the grafts functioned well and were found patent two years after surgery.

Mitral valve replacement for lupus valvulitis.

This paper describes a 47-years old patient with the history of lupus valvulitis for six and a half years, who had implantation of a Starr-Edwards prosthesis for a mitral insufficiency four years ago. This case represents the longest survival reported so far after mitral valve replacement for lupus valvulitis.

The influence of a therapeutic dose of nitroglycerin on invasive and non-invasive parameters of left ventricular performance in coronary heart disease.

To assess the influence of a therapeutic dose of 0.5 mg sublingual nitroglycerin (NTG) on left ventricular performance, 32 patients with coronary heart disease were studied. After routine coronary angiography the patients underwent cinearteriography and phonomechanocardiography before and four minutes after NTG administration. After NTG, end-diastolic pressure and systolic aortic pressure fell significantly, while heart rate, ejection fraction and dp/dt increased. After NTG, a significant prolongation of the pre-ejection period index (PEPI) and isovolumetric relaxation time (IVRT), increase in the PEP/LVET ratio and decrease of the "a" wave of the apexcardiogram were found. The usual therapeutic sublingual NTG dose causes profound haemodynamic changes which are due to decreased preload and afterload and altered contractility induced by NTG.

Panconductional defect in mixed connective tissue disease: association with Sjogren's syndrome.

A patient in whom mixed connective tissue disease in association of Sjögren's syndrome had previously been diagnosed, experienced a syncopal attack. Electrocardiographic monitoring revealed periods of profound sinus bradycardia, sinus arrest with slow junctional escape rhythm, and first degree atrioventricular block during several episodes of dizziness. Complete right bundle branch block was a constant finding in this patient. Sinoatrial conduction time and sinus node recovery time were prolonged. Coronary heart disease was excluded by normal coronary arteriographic findings. This patient represents a rare case of cardiac involvement in mixed connective tissue disease.