Cardiac autonomic innervation.

The autonomic nervous system plays a key role in regulating changes in the cardiovascular system and its adaptation to various human body functions. The sympathetic arm of the autonomic nervous system is associated with the fight and flight response, while the parasympathetic division is responsible for the restorative effects on heart rate, blood pressure, and contractility. Disorders involving these two divisions can lead to, and are seen as, a manifestation of most common cardiovascular disorders. Over the last few decades, extensive research has been performed establishing imaging techniques to quantify the autonomic dysfunction associated with various cardiovascular disorders. Additionally, several techniques have been tested with variable success in modulating the cardiac autonomic nervous system as treatment for these disorders. In this review, we summarize basic anatomy, physiology, and pathophysiology of the cardiac autonomic nervous system including adrenergic receptors. We have also discussed several imaging modalities available to aid in diagnosis of cardiac autonomic dysfunction and autonomic modulation techniques, including pharmacologic and device-based therapies, that have been or are being tested currently.

Idiopathic Atrial Fibrillation and Coronary Arteriovenous Fistulae: Is There a Link.

Despite being one of the most prevalent cardiac arrhythmias, the cause of atrial fibrillation (AF) in a vast majority of patients remains unknown. There is growing evidence of associated AF in patients diagnosed with coronary arteriovenous fistula. In this discussion, we have included an example of a patient who presented with new-onset AF and was subsequently diagnosed with an anomalous fistula between the right coronary artery and the superior vena cava. Definitive treatment of the fistula resulted in permanent resolution of the AF. Based on this case and a similar case reported in the literature, it is proposed that further research will unmask this possibly underdiagnosed and very treatable cause of AF.

Cardiac Tamponade Physiology Secondary to Tense Ascites.

Cardiac tamponade is a common and often life-threatening process, which is typically associated with a pericardial effusion or, in rare cases, with a large pleural effusion. Theoretically, as reported in only a single prior case, it can be caused by extrinsic compression from tense ascites. We present a case in which dynamic inferior wall collapse was secondary to increased abdominal pressure from tense ascites. This phenomenon may be more common than previously diagnosed, especially in patients with liver disease. These patients often develop frequent ascites and present with clinical signs and symptoms similar to cardiac tamponade (tachycardia, hypotension and dyspnea). Presently, no formal practice guidelines exist regarding cardiac imaging for these patients. A high index of suspicion is required for timely diagnosis and management.

Circumferential resection margin rates in esophageal cancer resection- oncological equivalency and comparable clinical outcomes between open versus minimally invasive techniques: A retrospective cohort study.

BACKGROUND: Radical surgery for esophageal cancer requires macroscopic and microscopic clearance of all malignant tissue. A critical element of the procedure is achieving a negative circumferential margin (CRM) to minimize local recurrence. The utility of minimally invasive surgery poses challenges in replicating techniques developed in open surgery, particularly for hiatal dissection in esophago-gastrectomy. In this study, the technical approach and clinical and oncological outcomes for open and laparoscopic esophago-gastrectomy are described with particular reference to CRM involvement. MATERIALS AND METHODS: This cohort study included all patients undergoing either open or laparoscopic esophago-gastrectomy between January 2004 to June 2022 in a single tertiary center. A standard surgical technique for hiatal dissection of the esophago-gastric junction developed in open surgery was adapted for a laparoscopic approach. Clinical parameters, length of stay (LOS), post-operative complications and mortality data were collected and analyzed by a Mann-Whitney U or Fisher's exact method. RESULTS: Overall 447 patients underwent an esophago-gastrectomy in the study with 219 open and 228 laparoscopic procedures. The CRM involvement was 18.8% in open surgery and 13.6% in laparoscopic surgery. The 90-day-mortality for open surgery was 4.1% compared with 2.2% for laparoscopic procedures. Median Intensive care unit (ITU), inpatient LOS and 30-day readmission rates were shorter for laparoscopic compared with open esophago-gastrectomy (ITU: 5 versus 8 days, P=0.0004; LOS: 14 versus 20 days, P=0.022; 30-day re-admission 7.46% versus 10.50%). Post-operative complication rates were comparable across both cohorts. The rates of starting adjuvant chemotherapy were 51.8% after open and 74.4% in laparoscopic esophago-gastrectomy. CONCLUSION: This study presents a standardized surgical approach to hiatal dissection for esophageal cancer. We present equivalence between open and laparoscopic esophago-gastrectomy in clinical, oncological and survival outcomes with similar rates of CRM involvement. We also observe a significantly shorter hospital length of stay with the minimally invasive approach.

Venoarterial PCO2 difference: a marker of postoperative cardiac output in children with congenital heart disease.

OBJECTIVE: To determine the relationship between venoarterial carbon dioxide gradient (DeltapCO2) and central venous oxygen saturation (ScvO2) in children after cardiac surgery. STUDY DESIGN: A cohort study. PLACE AND DURATION OF STUDY: The Paediatric cardiac intensive care unit of the Aga Khan University Hospital, Karachi, from June 2006 to May 2007. METHODOLOGY: All children admitted in the paediatric cardiac intensive care after complete repair of congenital heart defect using cardiopulmonary bypass were included in the study. Simultaneous arterial and central venous blood gas samples were obtained from a catheter placed in the artery (either radial or femoral) and superior vena cava respectively. Linear regression analysis was performed between ScvO2 and DeltapCO2. RESULTS: Fifty seven children aged from 5 days to 14 years were included and 272-paired simultaneous arterial and central venous samples were analyzed. Mean venous pCO2 was 47.82+/-9.03 mmHg and mean arterial pCO2 was 40.50+/-9.06 mmHg. One hundred seventy four samples had ScvO2 > 70% with mean DeltapCO2 of 5.44+/-2.55 mmHg and 98 samples had ScvO2 < 70% with mean DeltapCO2 of 9.07+/-3.90 mmHg. With ScvO2 < 70%, 77 samples had DeltapCO2 of > 6 mmHg while only 21 samples had DeltapCO2 of < 6 mmHg (p < 0.001). On the contrary with ScvO2 > 70%, 71 samples had DeltapCO2 of > 6 mmHg and 103 samples had DeltapCO2 of < 6 mmHg. Coefficient of correlation (R2) between 0.340 was ScvO2 and DeltapCO2. CONCLUSION: Elevated DeltapCO2 is practical and can be utilized as a useful adjunct to low ScvO2 in the assessment of low cardiac output syndrome in children after cardiac surgery.

Prediction of acute left main coronary artery obstruction by 12-lead electrocardiography. ST segment elevation in lead aVR with less ST segment elevation in lead V(1).

OBJECTIVES: We sought to determine the electrocardiographic (ECG) features associated with acute left main coronary artery (LMCA) obstruction. BACKGROUND: Prediction of LMCA obstruction is important with regard to selecting the appropriate treatment strategy, because acute LMCA obstruction usually causes severe hemodynamic deterioration, resulting in a less favorable prognosis. METHODS: We studied the admission 12-lead ECGs in 16 consecutive patients with acute LMCA obstruction (LMCA group), 46 patients with acute left anterior descending coronary artery (LAD) obstruction (LAD group) and 24 patients with acute right coronary artery (RCA) obstruction (RCA group). RESULTS: Lead aVR ST segment elevation (>0.05 mV) occurred with a significantly higher incidence in the LMCA group (88% [14/16]) than in the LAD (43% [20/46]) or RCA (8% [2/24]) groups. Lead aVR ST segment elevation was significantly higher in the LMCA group (0.16 +/- 0.13 mV) than in the LAD group (0.04 +/- 0.10 mV). Lead V(1) ST segment elevation was lower in the LMCA group (0.00 +/- 0.21 mV) than in the LAD group (0.14 +/- 0.11 mV). The finding of lead aVR ST segment elevation greater than or equal to lead V(1) ST segment elevation distinguished the LMCA group from the LAD group, with 81% sensitivity, 80% specificity and 81% accuracy. A ST segment shift in lead aVR and the inferior leads distinguished the LMCA group from the RCA group. In acute LMCA obstruction, death occurred more frequently in patients with higher ST segment elevation in lead aVR than in those with less severe elevation. CONCLUSIONS: Lead aVR ST segment elevation with less ST segment elevation in lead V(1) is an important predictor of acute LMCA obstruction. In acute LMCA obstruction, lead aVR ST segment elevation also contributes to predicting a patient's clinical outcome.

Forskolin potentiates myocardial reactive hyperaemia in the open chest dog: the contribution of adenylate cyclase.

Forskolin, a diterpene, directly stimulates adenylate cyclase and also potentiates receptor mediated stimulation of this enzyme by many stimulatory agonists. We exploited the potentiating effect of forskolin to test the hypothesis that activation of adenylate cyclase contributes to myocardial reactive hyperaemia, especially by release of adenosine at the time of brief coronary occlusions. In 10 open chest dogs, intracoronary forskolin infusions which produced plasma concentrations between 0.22 and 0.34 mumol.litre-1 slightly increased coronary blood flow and had no effect on haemodynamics or myocardial metabolism. Under these conditions, though peak reactive hyperaemic flow rates were not affected, forskolin infusions reversibly potentiated repayments of flow debt by 28, 25 and 27% following coronary occlusions of 15 s, 20 s and 30 s, respectively (p less than 0.05). In another seven dogs, after observations of the effects of forskolin (0.16-0.26 mumol), 10 mumol of 8-phenyltheophylline, a potent adenosine antagonist, was infused simultaneously with forskolin into the coronary arteries. Forskolin increased debt repayments by about 23-27% following 15 s, 20 s and 30 s occlusions, but with simultaneous 8-phenyltheophylline, forskolin induced increments in the debt repayments were reduced significantly (p less than 0.05). These results indicate that adenylate cyclase contributes to myocardial reactive hyperaemia, and adenosine has a significant role as metabolic regulator of reactive hyperaemia through activation of adenylate cyclase.

Q-wave regression unrelated to patency of infarct-related artery or left ventricular ejection fraction or volume after anterior wall acute myocardial infarction treated with or without reperfusion therapy.

We examined the relation of Q-wave regression to left ventricular (LV) indexes in acute anterior wall myocardial infarction (AMI) in relation to reperfusion therapy. A total of 94 patients with their first anterior wall AMI (segment 6 or 7 occlusion according to the American Heart Association classification) were examined. The follow-up period with 12-lead electrocardiograms ranged from 6 to 60 months (mean 24 +/- 18). An abnormal Q wave was defined as > 40 ms and > 25% of the R-wave amplitude. Q-wave regression was defined as Q-wave disappearance and r-wave regression > 0.1 mV in > or = 1 lead. Contingency tables with the chi-square test and analysis of variance were used for assessment of the relation between Q-wave regression and angiographic and clinical indexes. Q-wave regression in > or = 1 lead was found in 77% of the patients. The incidence of Q-wave regression in patients with patent infarct-related artery (81%) was not significantly different from that in those with an occluded lesion (67%). Q-wave regression appeared within 1 month in 60% of patients with a patent infarct-related artery but in 25% of those with an occluded lesion. No difference in the incidence of Q-wave regression was seen between patients with lesions at segments 6 (81%) and 7 (70%), or between those with (75%) and without (77%) collateral circulation. Q-wave regression did not correlate with LV ejection fraction, LV end-diastolic or end-systolic volumes, or regional wall motion.(ABSTRACT TRUNCATED AT 250 WORDS)

Primary cardiac angiosarcoma with superior vena caval syndrome: review of surgical resection and interventional management of venous inflow obstruction.

Primary cardiac angiosarcoma occurs rarely, and surgical resection is often required to relieve symptoms. A 66-year-old man whose presenting symptoms were palpitations and general fatigue is presented. Echocardiography revealed a large tumour occupying most of the right atrium. When superior vena caval (SVC) syndrome developed, surgical resection of the tumour was attempted. The tumour was found to have invaded the inflow of SVC, left atrium, right ventricle and ascending aorta. The bulk of the tumour was resected, requiring reconstruction of the right atrium and caval inflows. Histopathological diagnosis of the tumour was primary angiosarcoma. In the postoperative period, symptoms of SVC syndrome recurred, which were relieved temporarily by balloon angioplasty. After one month, recurrence of symptoms was again managed by catheter dilation. On this occasion a metallic stent was deployed, which prevented further symptoms of SVC syndrome during the eight months before the patient died with generalized metastases.

Transesophageal echocardiography for detection of mitral regurgitation due to papillary muscle rupture or dysfunction associated with acute myocardial infarction: a report of five cases.

Severe mitral regurgitation was associated with cardiogenic shock in five (0.8%) of 623 patients with acute myocardial infarction who were urgently admitted to the authors' hospitals between 1994 and 1996. The infarct was located in the inferior wall in four patients and in the inferoposterior wall in one patient. Severe mitral valve regurgitation occurred concurrently with cardiogenic shock between one and six days after the onset of myocardial infarction. A mitral regurgitant murmur was not audible in four of five patients. Similarly, mitral regurgitant Doppler signals were not detected in four patients by transthoracic echocardiographic examination, while transesophageal echocardiographic examination detected mitral regurgitant signals clearly in all patients. Thus, when cardiogenic shock is unexpectedly associated with inferior or inferoposterior wall acute myocardial infarction, severe mitral regurgitation should be suspected, even when a mitral regurgitant murmur is not audible. Furthermore, mitral regurgitant flow signals may not always be detected by transthoracic echocardiography. Thus, examination for mitral regurgitation by transesophageal echocardiography should be considered.

Coronary to bronchial artery anastomosis in patients with noncyanotic cardiopulmonary disease: report of seven cases.

An angiographically visible coronary to bronchial artery anastomosis was found in seven (0.12%) of 6045 patients with noncyanotic cardiopulmonary disease who underwent coronary angiography between 1989 and 1995. Aortitis syndrome was associated with four patients, whereas pulmonary embolism, aortic regurgitation and vasospastic angina were the diagnoses in the others. Coronary stenotic lesions were not observed in any patients. In five of six patients who underwent pulmonary perfusion scintigraphy, perfusion defect was observed in the area supplied by the bronchial artery, which had the anastomosis to the coronary artery. In each patient this anastomosis seemed to function as collateral circulation, compensating for decreased perfusion in either the lung or the heart. When coronary to bronchial artery anastomosis is found, ischemic conditions in either the lung or the heart are likely.

Progression of left ventricular enlargement in patients with hypertrophic cardiomyopathy: incidence and prognostic value.

A total of 51 patients with hypertrophic cardiomyopathy (HCM) were followed for at least 3 years (mean follow-up period 6.5 years) by serial M-mode and two-dimensional echocardiography. An increase of the left ventricular diastolic dimension (LVDd) to > or = 55 mm with a decrease in the left ventricular ejection fraction (LVEF) to < 55% was observed in eight (15.7%) patients (progressive disease group). In five of these eight patients, the LVDd was > or = 60 mm and the LVEF was < 40%. Ventricular enlargement was closely related to mortality and death due to congestive heart failure occurred in three of these patients. No deaths occurred among the 37 patients without significant progression of ventricular enlargement (nonprogressive group). The annual changes of LVEF and LVDd in the progressive disease group were larger than in the nonprogressive group (LVEF -0.18 +/- 1.45 vs. -2.46 +/- 1.47 %/year; LVDd 0.22 +/- 0.81 vs. 1.43 +/- 0.77 mm/year). An increment in LVDs occurred earlier than the enlargement of the LVDd. Therefore, close attention to the LVDs seems to be important to detect early left ventricular morphological changes in HCM. In summary, this study indicates that HCM patients include a subgroup with symptoms resembling dilated cardiomyopathy, in whom the left ventricle enlarges with hypofunction and in whom there is high mortality due to congestive heart failure.

Histological abnormalities in a biopsy specimen obtained from the left ventricle without reduced function in a patient with right ventricular dysplasia.

Left ventricular histological examination was performed in a patient with right ventricular (RV) dysplasia. Although the left ventricle (LV) appeared to have a normal shape and function, the LV biopsy specimen revealed apparent myocyte hypertrophy and substantial fibrotic changes without fatty infiltration. It was not clear whether these considerable histological changes were part of right ventricular dysplasia or not. The present case indicates that even with normal LV shape and function in patients with right ventricular dysplasia, histological examination of LV may provide additional information on its pathogenesis and prognosis.

Effect of heart rate and myocardial contractile force on coronary resistance.

The effect of the heart rate and myocardial contractile force on the extravascular resistance to blood flow of the left anterior descending coronary artery (LAD) was evaluated in 15 mongrel dogs anesthetized with sodium pentobarbital. The LAD was maximally dilated by intracoronary infusion of adenosine, which precluded the influence of vasomotor tone. Increases in the heart rate and myocardial contractile force decreased coronary blood flow in the absence of a change in coronary perfusion pressure. The changes in mean coronary resistance showed a significant linear relationship to changes in developed tension. The changes in coronary resistance caused by varying the heart rate and contractile force were so small that a normal coronary vascular tree could easily compensate for the increase in resistance. However, it is supposed that with critical stenosis of the vascular tree even a small increase in resistance might cause deleterious effects on coronary blood flow.

Factors influencing acute high-grade restenosis in emergency percutaneous transluminal coronary angioplasty for acute myocardial infarction.

We studied the factors which may induce acute high grade restenosis in emergency percutaneous transluminal coronary angioplasty (PTCA). PTCA was attempted in 50 patients with acute myocardial infarction, and the balloon catheter passed successfully across the occlusion site in 47 (94%) of the patients. These 47 patients were analyzed. "Acute restenosis" was defined as a lesion which was revascularized to less than 50% luminal reduction narrowed again to more than 75% luminal reduction 5 min after the balloon inflation. Univariate and multivariate analyses were used for determining factors which significantly influenced acute restenosis. The incidence of at least one restenosis episode was 45%. Multiple regression analysis selected 5 factors associated significantly with an increased rate of acute restenosis: 1) angiographic evidence of dissection, 2) lesion in the right coronary artery (RCA), 3) lack of or insufficient administration of thrombolytic agent preceding PTCA, 4) curved lesion and 5) relatively small balloon/artery diameter ratio. Acute restenosis correlated significantly with late reocclusion. This study indicates that it is important to administer a thrombolytic agent prior to emergency PTCA, and to use an adequately sized balloon to the artery when the acute restenosis occurs by using relatively smaller sized balloon. The present data also demonstrated that patients with RCA and a curved lesion have a relatively high risk of acute restenosis. This study indicates how patients with relatively high risk of acute restenosis may be identified.

Coronary flow reserve after coronary intervention in similar in patients with preserved viability in previous myocardial infarction and in those with angina pectoris.

The relationship between coronary flow reserve (CFR) and viability in the infarcted myocardium has not been fully clarified. We measured coronary blood flow velocity immediately after coronary intervention (with percutaneous transluminal coronary angioplasty [PTCA] or stenting) in 38 patients with previous myocardial infarction and preserved viability and 48 with angina pectoris. CFR was calculated and was similar between the two patient groups. No differences in the incidence of post-intervention CFR > 2.0 were detected; there were no differences in post-intervention CFR between patients with preserved myocardial viability and those with angina pectoris who underwent PTCA. Coronary stenting reduced the percentage diameter stenosis in both groups compared with PTCA and slightly increased the post-intervention CFR. No differences were, however, detected in post-intervention CFR between patients with preserved myocardial viability and those with angina pectoris who underwent additional stenting. These results reveal that in patients with preserved myocardial viability, post-intervention CFR was restored to values similar to those in patients with angina pectoris.

[Studies on the method of measurement of odorants dissolved in water--the simplified head space method].

An improved and simplified Head Space Method was devised for measurement of the concentration of odorants dissolved in waste water, and this method was examined to determine whether it was applicable for this purpose or not. This method is taken into consideration the variableness of liquid concentration and of gas pressure resulting from the volatilization of odorants and aqueous vapor to the atmosphere. By this method, the constants of hydrogen sulfide, dimethylsulfide and trimethylamine were measured under various temperatures and pHs. As a result of comparison with the measured values obtained by the Stripping Method and those from the heretofore used Head Space Method, this method appeared to be fairly applicable.

[A case of acute myocardial infarction due to simultaneous occlusion of the right coronary artery and left anterior descending coronary artery].

We reported a rare case of a 53-year-old man who experienced acute myocardial infarction due to simultaneous occlusion in the right coronary artery and the left anterior descending coronary artery. He also experienced thromboembolisms on several occasions. So anticoagulant therapy is necessary for patients with exceedingly poor LV function.