Effect of cardiac dysrhythmia on cerebral perfusion

Extracranial carotid arterial obstructive disease has been the entity most commonly associated with transient cerebrovascular insufficiency. A nonobstructive, frequently overlooked cause of cerebral ischemia is cardiac dysrhythmia. We have explored this by observations of experimental animals and of man. Blood flow and pressure in the carotid arteries of dogs were shown to be decreased by mechnically induced premature ventricular contractions. The significance of the cardiogenic contribution to altered cerebrovascular perfusion was studied by ocular and brachial plethysmography in 210 patients suspected by history of having carotid arterial insufficiency. Of the 210 patients, 62 demonstrated abnormal ocular plethysmographic recordings, and of those, nine had dysrhythmias associated with significant deficits of ocular perfusion. Five patients whose recordings were technically suitable for publication are presented to demonstrate the bizarre ocular plethysmographic recordings seen during the dysrhythmic cycle.     

Alteration in diaphragmatic function during cardiac insufficiency: potential pharmacology modulation

Respiratory muscle dysfunction has been demonstrated in several clinical situations including chronic respiratory disease, such as chronic obstructive pulmonary disease, as well as cardiac insufficiency. In the latter case, respiratory muscle dysfunction has been demonstrated in acute situation (cardiogenic shock) and in chronic cardiac insufficiency. In the former case, it has been shown in an animal model that respiratory muscle dysfunction could influence markedly the outcome of cardiogenic shock. In chronic cardiac insufficiency histologic, biochemical and contractile abnormalities of the respiratory muscles have been demonstrated in an animal model as well as in humans. These alterations may account, at least in part, for the sensation of dyspnea that these patients encountered. Finally, several pharmacological agents such as angiotensin-converting enzyme inhibitors have been shown to restore muscle abnormalities observed during chronic cardiac insufficiency.     

Validity of cardiac output measurement by the thermodilution method in the presence of acute tricuspid regurgitation

Evaluation of patients with acute tricuspid insufficiency may include assessment of cardiac output by the thermodilution method. The accuracy of estimates of thermodilution-derived cardiac output in the presence of tricuspid insufficiency has been questioned. This study was designed to determine the validity of the thermodilution technique in a canine model of acute reversible tricuspid insufficiency. Cardiac output as measured by thermodilution and electromagnetic flowmeter was compared at two grades of regurgitation. The relationship between these two methods (thermodilution/electromagnetic) changed significantly from a regression slope of 1.01 +/- 0.18 (mean +/- standard deviation) during control conditions to a slope of 0.86 +/- 0.23 (p < 0.02) during severe regurgitation. No significant change was observed between control and mild regurgitation or between the initial control value and a control measurement repeated after tricuspid insufficiency was reversed at the termination of the study. This study shows that in a canine model of severe acute tricuspid regurgitation the thermodilution method underestimates cardiac output by an amount that is proportional to the level of cardiac output and to the grade of regurgitation.     

Use of glucagon in the treatment of severe contractile insufficiency of the myocardium

Glucagon hydrochloride has been used to treat severe contractile insufficiency of the myocardium. The drug was administered to cardiopathic patients who had been admitted to the intensive care unit. Results in the various groups examined were satisfactory, particularly in cases of patients with valve diseases and with chronic pulmonary heart and cardiac insufficiency recalcitrant to digitalis therapy. No important side-effects were noted.     

Mechanism for improved cardiac performance with arteriolar dilators in aortic insufficiency

To determine how arteriolar dilation improves cardiac performance in aortic insufficiency, we evaluated the acute effects of hydralazine in 10 patients with chronic severe aortic insufficiency. Control measurements of intracardiac and intravascular pressures, cardiac output and left ventricular volumes were obtained at cardiac catheterization. Hydralazine, 0.3 mg/kg i.v. (maximal dose 20 mg), was administered and all measurements were repeated 30 minutes later. A reduction in systemic vascular resistance from 1264 to 710 dyn-sec-cm-5 was associated with significant increases in forward cardiac index (2.9 to 5.1 l/min/m2) and stroke volume index (37 to 55 ml/m2). Left ventricular end-diastolic pressure was reduced from 19 to 12 mm Hg. There was a significant reduction in mean arterial pressure (88 to 83 mm Hg) and a significant increase in heart rate (81 to 94 beats/min). Regurgitant stroke volume was reduced by more than 10 ml/m2 in seven patients and for the group was significantly reduced, from 65 to 53 ml/m2. Regurgitant fraction was reduced in all patients; the overall reduction from 0.64 to 0.48 was highly significant. Ejection fraction increased more than 0.10 in four patients, by 0.08 in an additional patient and for the group increased significantly from 0.50 to 0.57. Left ventricular end-diastolic volume decreased by more than 25 ml/m2 in four patients, by 19 ml/m2 in an additional patient and was decreased significantly, from 208 to 190 ml/m2, for the group. Arteriolar dilators improve cardiac performance in aortic insufficiency by reducing the amount of aortic regurgitation and, in some patients, by substantially improving systolic pump fraction. These data suggest a role for arteriolar dilators in the management of selected patients with aortic insufficiency.     

The renal factor in the post-traumatic "fluid overload" syndrome

Hypervolemia with hypertension often occurs 36-72 hours following massive blood and fluid replacement for hypovolemic shock. This syndrome of "fluid overload" has been attributed to the rapid intravascular flux of previously sequestered fluid in patients with impaired diuresis. This hypothesis was tested in 35 injured patients who received a mean of 9.3 L of blood and 17.4 L of salt during resucitation. The renal parameters measured soon after resuscitation included: 1) renal clearance of inulin (GFR), para-amino hippurate (ERPF), milliosmoles, sodium, and free water; 2) inulin space, renal vascular resistance (RVR), O2 consumption, renin, renal blood flow (RBF), and response to furosemide. Eighteen patients developed hypertension, hypervolemia, and respiratory insufficiency. When compared to the 17 normovolemic, non-hypertensive patients, the 18 hypervolemic patients had significantly increased RVR, with a significant decrease in RBF despite an increase in plasma volume and cardiac output. Furosemide produced less diuresis and natriuresis in the hypertensive patients. The balance between hypovolemia and "fluid overload" seemed percarious in the hypertensive patients. Peripheral renin and catecholamine levels were normal in both groups. Patients with post-traumatic "fluid overload" appear to have a combination of hypervolemia, respiratory insufficiency, hypertension, increased cardiac output, decreased extracellular fluid space, and decreased renal perfusion. These findings suggest that decreased interstitial fluid space compliance rather than "fluid overload" is the underlying factor leading to respiratory insufficiency. The therapeutic aspects of these findings are discussed.     

Serum neuron-specific enolase as early predictor of outcome after cardiac arrest

OBJECTIVE: To examine the prognostic value of serum neuron-specific enolase for early prediction of outcome in patients at risk for anoxic encephalopathy after cardiac arrest. DESIGN: Prospective study. SETTING: Coronary intensive care unit of the University of Heidelberg. PATIENTS: Forty-three patients (66.8 +/- 12.7 [SD] yrs, range 33 to 85) who had had either primary or secondary cardiac arrest, followed by cardiopulmonary resuscitation (CPR). INTERVENTIONS: Serial blood samples and clinical examinations. MEASUREMENTS AND MAIN RESULTS: Serum neuron-specific enolase concentrations were determined after CPR on 7 consecutive days. Twenty-five patients remained comatose and subsequently died; 18 patients survived the first 3 months and had no relevant functional deficit at 3-month follow-up. Neuron-specific enolase concentrations were correlated with neurologic outcome. Concentrations of >33 ng/mL predicted persistent coma with a high specificity (100%) and a positive predictive value of 100%. Overall sensitivity was 80%, with a negative predictive value of 78%. Serum concentrations of neuron-specific enolase exceeded this cutoff value no more than 3 days after cardiac arrest in 95% of patients in whom these concentrations had exceeded 33 ng/mL. CONCLUSIONS: In patients who have been resuscitated after cardiac arrest, serum neuron-specific enolase concentrations of >33 ng/mL predict persistent coma with a high specificity. Values below this cutoff level do not necessarily indicate complete recovery, because this method has a sensitivity of 80%.     

Clinical observation of cardiac pacemaker in pregnant women

OBJECTIVE: To study the clinical results in pregnant women with bradycardia implanted with cardiac pacemakers. METHOD: Five pregnant women with bradycardia were retrospectively studied in our hospital from 1980 to 1996. RESULTS: Four of the patients had A-V block, and the other one sinus bradycardia. Classification of cardiac function, showed 1 case of class IV, 3 cases of class III, and 1 case of class II before implantation of cardiac pacemaker. One case had the pacemaker implanted before pregnancy and 4 cases during pregnancy. Cardiac function improved significantly after implantation and pregnancies went uneventfully. Three women had term living birth by cesarean section, and 2 ended by therapeutic abortions safely. CONCLUSION: Bradycardia is a rare and serious complication in pregnancy, especially due to A-V block of III degree. Cardiac pacemaker should be implanted before pregnancy or at early stage of pregnancy in order to maintain adequate heart function. These patients should receive cesarean section.     

Differentiation of myoendocrine cardiac cells from presumptive heart mesoderm explants of Bufo arenarum

To investigate which factors are involved in the differentiation of Bufo arenarum heart myoendocrine cells, we studied the distribution of Atrial Natriuretic Peptide (ANP) immunoreactivity in hearts formed from presumptive cardiac mesoderm explanted at early embryo stages. Explants isolated from different embryonic stages throughout neurulation were cultured in vitro with or without the pharyngeal endoderm, and in other cases transplanted to the caudal region of embryos at similar stages. We utilized immunohistochemical and morphological techniques to assess myoendocrine cardiac cell differentiation. Development of heart beat and positive tropomyosin immunolabeling were considered signs of cardiac tissue differentiation. Our results confirm that explants of cardiac mesoderm cultured with endoderm showed a greater and more complete level of cardiac differentiation than those of mesoderm alone, and this coincides with the staining pattern of tropomyosin. ANP immunostaining revealed that cardiac cells containing ANP were scarce in those cultures without endoderm. On the contrary, in both cultured and grafted explants containing endoderm, ANP immunostaining was intensive and well-distributed in the cardiac tube, and in some cases restricted to one side of the formed heart. We conclude that the endoderm regulates cardiac cell differentiation, and in this way, is involved in the development of the heart myoendocrine system.     

Quality of life in chronic venous insufficiency (CVI). Results of a study with the newly developed Tübingen Questionnaire for measuring quality of life of patients with chronic venous insufficiency

Across the boundaries of the medical specialties we have realized how important the concepts of quality of life and disease-related coping behavior are to understand the patients' subjective perception of the medical condition and its treatment. Although standardized instruments are already available for different medical indications and even in the related fields of peripheral vascular and cardiac diseases, phlebology still lacks standardized concepts for evaluating quality of life and/or disease-related coping behavior in patients with chronic venous insufficiency (CVI). We report on a newly developed instrument specifically designed for recording quality of life in patients with CVI. It not only meets the requirements of psychometric standards, but has also proven its applicability in clinical use. The "Tübingen Questionnaire for measuring Quality of Life in patients with CVI (TLQ-CVI)" and the results of a study on quality of life in 142 patients with various stages of chronic venous insufficiency are presented. It was possible to distinguish between Stage I/II and Stage III CVI patients with respect to parameters such as "leg complaints" and "day-to-day fears and worries". These convey clinically relevant insights into the patient's subjective perception of the disease and how they cope. The information gathered provides a set of reasonable target scores for clinical studies presently being carried out at various study centers in Germany incorporating the TLQ-CVI.     

Effects of low doses of ionizing radiation and induced hypothyroidism on the course of pregnancy and the development of the offspring in rats

OBJECTIVES: To determine the appropriate indications and timing for surgery in children with either a perimembranous or a subarterial type of ventricular septal defect (VSD) associated with aortic cusp prolapse. DESIGN: Retrospective review of children with VSD and associated aortic cusp prolapse with or without aortic regurgitation. This review was based on data obtained from clinical findings, two-dimensional echocardiography, cardiac catheterization and angiocardiography. SETTING: Tertiary health care facility with two-dimensional and colour Doppler echocardiographic and cardiac surgery facilities, and a catheterization laboratory. PATIENTS: Forty-eight patients were found to have perimembranous or subarterial VSDs in association with aortic cusp prolapse with or without aortic regurgitation. INTERVENTIONS: All 48 patients had high resolution two-dimensional and colour Doppler echocardiography. Of the 19 patients who underwent surgical closure of their VSD, five also had an aortic valvuloplasty and one had an aortic valve replacement. Cardiac catheterization was performed in 16 of the 19 surgical patients and 12 of the 29 nonsurgical patients. MEASUREMENTS AND MAIN RESULTS: Annual clinical and echocardiographic assessments in the nonsurgical group did not demonstrate increasing aortic insufficiency. Two children in the nonsurgical group showed spontaneous resolution of aortic insufficiency. In the surgical group, four children with VSD and clinical aortic insufficiency had surgery at less than five years of age; two were found to be regurgitant-free, one had trivial clinical aortic insufficiency and the other had echocardiography-only insufficiency. Of the seven surgical patients older than five years with VSD and clinical aortic insufficiency, four were found to be regurgitant-free, one had echocardiography-only regurgitation and two were unchanged. Two children undergoing surgery with VSD and no aortic insufficiency had postoperative echocardiography-only regurgitation, presumably related to cusp deformity from presurgical prolapse. Children with large VSDs with or without aortic cusp prolapse required surgery for indications of shunt size and pulmonary resistance. CONCLUSIONS: For children with small perimembranous VSDs and cusp prolapse, surgery is indicated only if there is clinical evidence of aortic regurgitation and progressive left ventricular enlargement.     

Postoperative prognosis of congenital cardiac anomalies

Congenital cardiac anomalies cannot be merely classified as "less", "more", and "very" complex. However, postoperative prognosis is also determined by: the wide variability in severity of certain anomalies; their frequent association with other cardiac or non-cardiac malformations; age at the time of surgery; the era, mode and quality of initial and subsequent treatment. Chosen examples will illustrate how recent progress has altered prognosis. The role of early, specific and multidisciplinary care in an appropriate center is emphasized.     

Extracorporeal membrane oxygenator support for cardiopulmonary failure. Experience in 28 cases

We have used extracorporeal membrane oxygenation (ECMO) for 28 patients (14 children and 14 adults) over a 5 year period. Nine patients improved on ECMO and 5 were long-term survivors. ECMO was used for pulmonary insufficiency in 24 patients. Initially, only moribund patients were treated, but recently the combination of open lung biopsy and pulmonary insufficiency index (PII) has been used to select patients. The best results have been obtained in newborn cases and the adult capillary leak syndromes; the major problem has been progression to fibrosis despite ECMO support. ECMO was used for cardiac failure in 4 patients. Children with postoperative cardiac failure did the best; profound shock was not reversed with venoarterial bypass. ECMO support is lifesaving in selected cases of pulmonary insufficiency. Initial trials in cardiac failure and the infant age group in this series suggest that ECMO will have an even greater role in those applications.     

Time organization of blood coagulation in patients with rheumatic heart disease involving circulation insufficiency

Daily profiles of blood coagulation were studied in 20 normal subjects and 92 patients with rheumatic heart disease with stages I-III circulatory insufficiency before and after traditional therapy and chronotherapy with heparin and curantyl added to traditional therapy with antirheumatic agents, diuretics, and cardiac glycosides. Time organization of the hemostasis was disordered in patients with decompensated heart disease, but it is possible to correct it by chronotherapy with heparin and curantyl.     

Reexploration for bleeding is a risk factor for adverse outcomes after cardiac operations

OBJECTIVE: Although previous studies have included early reexploration for bleeding as a risk factor in analyzing adverse outcomes after cardiac operations, reexploration for bleeding has not been systematically examined as a multivariate risk factor for increased morbidity and mortality after cardiac surgery. Furthermore, multivariate predictors of the need for reexploration have not been identified. Accordingly, we performed a retrospective analysis of 6100 patients requiring cardiopulmonary bypass from January 1, 1986, to December 31, 1993. METHODS: Eighty-five patients who had ventricular assist devices were excluded from further analysis because of the prevalence of bleeding and the significant morbidity and mortality associated with placement of a ventricular assist device, unrelated to reexploration. In the remaining 6015 patients, potential adverse outcomes analyzed included operative mortality, mediastinitis, stroke, renal failure, adult respiratory distress syndrome, prolonged mechanical ventilation, sepsis, atrial arrhythmias, and ventricular arrhythmias. To control for the confounding effects of other risk factors, we performed a multivariate logistic regression analysis. Potential covariates considered in the logistic model included age, sex, race, history of reoperation, urgency of the operation, congestive heart failure, prior myocardial infarction, renal failure, diabetes, hypertension, chronic obstructive pulmonary disease or stroke, and the bypass and crossclamp time. RESULTS: The overall incidence of reexploration was 4.2% (253/6015). Four independent risk factors--increased patient age (p < 0.001), preoperative renal insufficiency (p = 0.02), operation other than coronary bypass (p < 0.001), and prolonged bypass time (p = 0.0.3)--were identified as predictors of the need for reexploration. The preoperative use of aspirin, heparin, or thrombolytic agents and the bleeding time were not identified as predictors. Reexploration for bleeding was identified as a strong independent risk factor for operative mortality (p = 0.005), renal failure (p < 0.0001), prolonged mechanical ventilation (p < 0.0001), adult respiratory distress syndrome (p = 0.03), sepsis (p < 0.0001), and atrial arrhythmias (p = 0.006). CONCLUSION: These data indicate that meticulous attention to surgical hemostasis and possibly application of recently developed modalities designed to facilitate perioperative correction of coagulopathy could improve outcomes after cardiac operations.     

Senning plus arterial switch operation for discordant (congenitally corrected) transposition

BACKGROUND: Congenitally corrected transposition of the great arteries is a complex cardiac lesion, usually associated with ventricular septal defect, left ventricular outflow tract obstruction, and tricuspid valve abnormalities. A subset of patients without left ventricular outflow tract obstruction have undergone Senning plus arterial switch operation in an attempt to place the left ventricle in the systemic circuit and the right ventricle in the pulmonary circuit. METHODS: Fourteen patients have had the operation performed since July 1989. Age and weight medians were 12 months (range, 0.5 to 120 months) and 8.2 kg (range, 3.2 to 34 kg). All but 1 patient had a left ventricular to right ventricular pressure ratio greater than 0.7, due to a large ventricular septal defect (with or without a previous pulmonary artery band), severe congestive heart failure caused by right ventricular dysfunction and tricuspid insufficiency, or a pulmonary artery band for left ventricular retraining. At least 10 patients had strong contraindications to "classic" repair, including right ventricular hypoplasia (n = 2), moderate to severe right ventricular dysfunction (n = 5), or moderate to severe tricuspid insufficiency (n = 9). RESULTS: There was one hospital death, occurring in a neonate (7%; 95% confidence interval = 0% to 34%). Actuarial survival beyond 10 months is 81% (95% confidence interval = 42% to 95%), currently with 389 patient-months of total follow-up time. The median grade of tricuspid insufficiency fell from 3/4 preoperatively to 1/4 postoperatively (p = 0.003). Right ventricular function is normal in 11/12 current survivors, all but 1 of whom are in New York Heart Association class I or II. CONCLUSIONS: Senning plus arterial switch operation is a good option for selected patients with congenitally corrected transposition of the great arteries with a similar or lower early risk (as compared with classic repairs). Some of the long-term problems associated with congenitally corrected transposition of the great arteries may be avoided with this strategy.     

Fungal endocarditis following cardiac surgery

This study examines the long-term prognosis of patients with an abnormal exercise radionuclide angiogram in the absence of significant angiographic coronary artery disease (CAD). In general, patients without significant CAD have an excellent prognosis, but the long-term outcome for the subset of patients with an "ischemic" exercise test is not known. In this study, 161 patients with normal coronary arteries or insignificant CAD (< 50% left main and < 70% left anterior descending, left circumflex, or right), resting left ventricular (LV) ejection fraction > or = 0.50, and an abnormal exercise radionuclide angiogram (LV ejection fraction that decreased with exercise or peak exercise LV ejection fraction < 0.60) were followed for a median duration of 11.3 years. The mean delta LV ejection fraction was -0.07, 98 patients (61%) had a decrease in LV ejection fraction of > or = 5 units, and 40 patients (25%) had peak exercise LV ejection fraction < 0.50. During follow-up there were 19 deaths (only 1 of which was cardiac), 7 nonfatal myocardial infarctions, and 9 revascularization procedures. At 12 years, overall survival was 88%, better than the expected survival for the age- and sex-matched general population. Survival free of cardiac death or myocardial infarction was 94% and survival free of any cardiac event including revascularization was 88%. Thus, patients with an abnormal exercise radionuclide angiogram but without significant CAD have an excellent long-term prognosis.     

Radiofrequency ablation of anomalous cardiac pathways: initial experience

AIM: To describe the initial experience of radiofrequency ablation of anomalous cardiac pathways in patients with supraventricular tachycardias. METHODS: A total of 10 patients with refractory supraventricular tachycardias mediated by anomalous cardiac pathways underwent electrophysiological assessment and attempted pathway ablation. RESULTS: Seven patients with left free wall atrioventricular pathways (two concealed) and two patients with dual atrioventricular nodal pathways had successful pathway ablations and have had no recurrence of arrhythmia. One patient with a concealed posteroseptal atrioventricular pathway was not able to be ablated. All patients tolerated the initial procedure well, but one developed pericarditis later. CONCLUSION: Radiofrequency ablation promises to be an important new technique for the management of patients with anomalous cardiac pathways and supraventricular tachycardias. Our initial experience has been favourable and comparable to other reported series with a high success rate and infrequent complications.     

Direct evidence of impaired cardiac sympathetic innervation in essential hypertensive patients with left ventricular hypertrophy

Increased sympathetic nervous activity has been proposed as one of the causes of left ventricular hypertrophy (LVH) associated with hypertension. However, the precise relationship is not fully understood. METHODS: To elucidate the relationship between myocardial sympathetic nervous activity and LVH in patients with essential hypertension EHT), we performed 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy in 49 patients with EHT and 17 normotensive control subjects. Sympathetic innervation of the left ventricle was evaluated using SPECT, and the whole heart uptake of the tracer was quantitatively assessed as the heart-to-mediastinum uptake ratio on both the early (15-min) and delayed (5-hr) images. Myocardial washout rate (MWR) of the tracer from 15 min to 5 hr after the isotope administration was also calculated. The left ventricular mass index (LVMI) was determined echocardiographically. RESULTS: In 49 hypertensive patients, there was a negative correlation between LVMI and heart-to-mediastinum uptake ratio on both the early and delayed images (r=-0.55, p < 0.0001; r=-0.63, p < 0.0001, respectively). In addition, there was a positive correlation between the LVMI and MWR of 123I-MIBG in these hypertensive patients (r=0.59, p < 0.0001). As for the regional uptake of the tracer, there was no significant difference between control subjects and hypertensive patients without cardiac hypertrophy, but a significant decrease of the uptake in the inferior and lateral regions was observed in hypertensive patients with cardiac hypertrophy. CONCLUSION: Patients with EHT had decreased accumulation and increased MWR of 123I-MIBG in proportion to the degree of LVH. Hypertensive patients with cardiac hypertrophy had impaired sympathetic innervation in the inferior and lateral regions of the left ventricle.     

Gastrointestinal complications after cardiac surgery

OBJECTIVE: Gastrointestinal (GI) complications after cardiac surgery with cardiopulmonary bypass (CPB) are uncommon complications with significant morbidity and mortality rates. METHODS: From 1988 to 1995, 36 GI complications were identified in 3158 patients who underwent cardiac surgery (1.14% incidence). The mortality rate was 13.9%. Complications included hemorrhage in the GI tract in 22, perforated ulcer in 3, acute cholecystitis in 3, pancreatitis in 2, mesenteric ischemia in 3, diverticulitis in 1 and liver failure in 2 patients. RESULTS: Clinical risk factors included advanced age, combined coronary artery bypass grafting (CABG)-valve operation, postoperative low cardiac output (LCO), prolonged ventilation time, re-exploration of the chest, sternal infection and a positive history of peptic ulcer. Patients with a prolonged pump time had an increased risk of GI complications (P < 0.001). CONCLUSIONS: Gastrointestinal complications, although of low incidence, carry a significantly high mortality, and the clinician must be alert to institute early appropriate treatment.