Cardiovascular impairment in a patient with acute myelitis.

STUDY DESIGN: Case report. OBJECTIVE: to report and discuss the development of sudden symptomatic sinus bradycardia in a 35-year-old woman with acute myelitis. CASE REPORT: A 35-year-old woman presented rapidly progressive weakness and hypoesthesia in the left hemibody. Five days after symptom onset, she developed symptomatic sinus bradycardia up to 30 b.p.m. Bradycardia was completely resolved ∼36 h after its onset. RESULTS: Cervical spine magnetic resonance imaging showed a focal T2-hyperintense intramedullary lesion at C2 level, with moderate cord swelling. The lesion involved bilaterally dorsal funiculi, and left lateral and ventral funiculi. Cardiac I-123 metaiodobenzylguanidine (MIBG) scintigraphy showed a decreased cardiac MIBG uptake suggesting sympathetic denervation. CONCLUSION: The most likely explanation for bradycardia in our patient is the myelitis-related disruption of descending vasomotor pathways, resulting in sympathetic hypoactivity. Our case extends the spectrum of the clinical presentations of cervical myelitis and emphasizes the importance of careful cardiac monitoring in acute phase of cervical myelitis.

Effect of bariatric surgery on peripheral flow-mediated dilation and coronary microvascular function.

BACKGROUND AND AIMS: To assess the effects of bariatric surgery (BS) on peripheral endothelial function and on coronary microvascular dilator function. METHODS AND RESULTS: We studied 50 morbidly obese patients (age 38 ± 9, 13 M) who underwent BS and 20 comparable obese controls (age 41 ± 11, 6 M) without any evidence of cardiovascular disease. Peripheral vascular dilator function was assessed by brachial artery diameter changes in response to post-ischemic forearm hyperaemia (flow-mediated dilation, FMD). Coronary microvascular function was assessed by measuring coronary blood flow (CBF) velocity response to i.v. adenosine and to cold pressor test (CPT) in the left anterior descending coronary artery by transthoracic Doppler echocardiography. The tests were performed at baseline and at 3-month follow-up. At baseline, FMD and CBF response to adenosine and CPT were similar in the 2 groups. Compared to baseline, FMD at follow-up improved significantly in BS patients (5.9 ± 2.7% to 8.8 ± 2.4%, p < 0.01), but not in controls (6.3 ± 3.2% vs. 6.4 ± 3.1%, p = 0.41). Similarly, a significant improvement of CBF response to adenosine (1.63 ± 0.47 to 2.45 ± 0.57, p < 0.01) and to CPT (1.43 ± 0.26 to 2.13 ± 0.55, p < 0.01) was observed in BS patients but not in controls (1.55 ± 0.38 vs. 1.53 ± 0.37, p = 0.85; and 1.37 ± 0.26 vs. 1.34 ± 0.21, p = 0.48, respectively). The favourable vascular effects of BS were similar independently of the presence and changes of other known cardiovascular risk factors and of basal values and changes of serum C-reactive protein levels. CONCLUSIONS: Our data show that, in morbidly obese patients, together with peripheral endothelial function, BS also improves coronary microvascular function. These effects suggest global improvement of vascular function which can contribute significantly to the reduction of cardiovascular risk by BS reported in previous studies.

Contrast transoesophageal echocardiography remains superior to contrast-enhanced cardiac magnetic resonance imaging for the diagnosis of patent foramen ovale.

AIMS: In 30-40% of patients with acute ischaemic stroke, the cause remains undefined (cryptogenic stroke). Contrast transoesophageal echocardiography (TEE) is considered the gold standard for patent foramen ovale (PFO) detection. Recently, however, cardiac magnetic resonance (CMR) has also been applied to detect PFO. In this study, we compared the diagnostic value of CMR and TEE in detecting PFO in a group of patients with apparently cryptogenic stroke. METHODS AND RESULTS: Twenty-five patients (age 50 ± 13 years, 16 males) with apparently cryptogenic ischaemic stroke underwent contrast-enhanced TEE and contrast CMR for detection of possible PFO. Both imaging studies were performed during Valsalva manoeuvre. PFO grading results were assessed visually both for TEE and for CMR, according to the entity of contrast passage in the left atrium (grade 0 = no PFO; grades 1, 2, and 3 = mild, medium, and wide PFO, respectively). TEE detected PFO in 16 patients (64%). Contrast-enhanced CMR identified a PFO in 7 (44%) of these patients. TEE showed a grade 1 PFO in five patients, a grade 2 PFO in eight patients, and a grade 3 PFO in three patients. Of these patients, CMR failed to identify PFO in all five patients with a grade 1 PFO, in one patient with a grade 2 PFO, and one patient with grade 3 PFO according to TEE. None of the nine patients without PFO at TEE was shown to have a PFO at CMR. When compared with TEE, the present methodology of CMR had a sensitivity of 50%, specificity of 100%, negative predictive value of 31%, and a positive predictive value of 100%. CONCLUSION: Our data suggest that TEE is the cornerstone imaging diagnostic test to detect and characterize PFO in patients with ischaemic stroke, and is shown to be better compared with the current CMR sequences.

Low glucose blood levels are associated with abnormal cardiac sympatho-vagal balance in type 2 diabetic patients with coronary artery disease.

BACKGROUND AND OBJECTIVES: Glycemic control has been suggested to improve prognosis in diabetic patients, but recent trials failed to show benefits from intensive glycemic control. Hypoglycaemic episodes or large variability in glucose blood levels causing a sympatho-vagal imbalance of cardiac autonomic function (CAF) might play a role in this result. In our study we assessed whether blood glucose fluctuation may be related to variations in CAF during daily life in diabetic patients with coronary artery disease (CAD). MATERIALS AND METHODS: Twelve patients with type 2 diabetes mellitus with CAD (65+/-4 years, 2 women) underwent simultaneous 48-hour ECG Holter monitoring and continuous interstitial glucose measurements. The highest and lowest glucose levels for each 3-hour segments of the day were identified and heart rate variability (HRV) parameters were measured on Holter recordings on 5-minute intervals centred on these times. RESULTS: Overall, 294 glucose levels were available for analysis. In the whole population several HRV indices were significantly lower in correspondence of the lowest glucose blood levels and this difference was much more evident in patients who were not taking beta-blockers, than in patients who were taking beta-blockers. A significant, although mild, correlation was found between glucose blood levels and several time-and frequency domain HRV variables in patients not taking beta-blockers, but not in these on beta-blockers therapy. DISCUSSION: Our data suggest that, in type 2 diabetic patients with CAD, hypoglycaemic episodes are associated with depressed HRV and that beta-blocking agents are able to contrast this relation. These interesting results merit to be investigated in a larger population of patients.

Association between reduced pulmonary diffusing capacity and cardiac autonomic dysfunction in Type 1 diabetes.

BACKGROUND: In Type 1 diabetes mellitus (DM), it has been suggested that autonomic nervous system dysfunction (NAD) impairs lung diffusion capacity. Heart rate variability (HRV), a measure of cardiac autonomic function, is a sensitive method of detecting NAD. To our knowledge, no previous study has assessed whether cardiac sympatho-vagal balance is associated with lung diffusion capacity in diabetes. METHODS: Twenty Type 1 DM patients without pulmonary abnormalities and systemic NAD underwent measurement of lung diffusion capacity for carbon monoxide (DLCO) by single-breath method and assessment of cardiac autonomic function by HRV analysis on 24-h electrocardiographic Holter recordings. RESULTS: Standard respiratory function tests and peripheral autonomic tests were normal in all patients. DLCO was lower than normal reference values in six patients (30%). DLCO correlated significantly with most HRV variables, independent of the clinical and laboratory variables. The strongest correlation was found with standard deviation of all RR intervals (SDNN; r = 0.62, P = 0.003) in the time domain and low frequency (LF) power (r = 0.73, P < 0.001) in the frequency domain. CONCLUSIONS: In Type 1 diabetes, a significant association exists between cardiac NAD and reduced DLCO in the absence of clinical respiratory and autonomic abnormalities. Thus, NAD may be involved in the early reduction of DLCO in these patients, possibly through abnormalities in the regulation of pulmonary blood flow at the microvascular level.

Effect of primary coronary intervention on heart rate variability and left ventricular function in patients with acute myocardial infarction.

AIM: Several studies showed that primary percutaneous coronary interventions (PCI) have a favourable impact on left ventricular remodeling and heart rate variability (HRV) both at short- and long-term follow-up in patients suffering an acute myocardial infarction (AMI). However, no previous study investigated the relationship between left ventricular remodeling and changes in HRV during follow-up in AMI patients treated by primary PCI. METHODS: We studied 28 patients with AMI (57+/-8 years, 27 men), treated by PCI within 12 hours of symptom onset. Patients underwent a 24-hour ECG Holter recording and left ventricular ejection fraction (LVEF) echocardiographic assessment before discharge, and at 1-month and 6-month follow-up. HRV was measured in the time- and frequency-domain. RESULTS: A significant improvement of both time- and frequency-domain HRV variables was observed at 1-month and at 6-month follow-up with the most significant changes being found for standard deviation of normal-normal beat intervals (SDNN) in the time-domain (95.5+/-26.1 ms vs 125.5+/-29.8 ms vs 142.8+/-28.8 ms, respectively; P<0.001) and for very low frequency (VLF) amplitude in the frequency-domain (36.7+/-9.8 ms vs 44.1+/-11.1 vs 48.9+/-12.2 ms, respectively; P<0.001). In contrast, compared to basal values, LVEF was substantially unchanged at 1-month and 6-month follow-up (48.8+/-8.5% vs 50.8+/-10% vs 49.6+/-9%, respectively; P=0.25). At 6-month follow-up 11 patients showed an improvement of >or= 5% of LVEF, whereas 17 patients did not show any improvement of LVEF. HRV variables significantly improved in a similar way in these two subgroups both at 1-month and at 6-month follow-up. CONCLUSION: Our data demonstrate that, in AMI patients treated by primary PCI, HRV improves over time, independent of changes in LVEF. The clinical implications of these findings deserve to be addressed in future studies.

Diagnostic and prognostic value of ST segment depression limited to the recovery phase of exercise stress test.

OBJECTIVES: To investigate the diagnostic and prognostic value of ST segment depression limited to the recovery phase of an exercise stress test, as compared with that of ST segment depression appearing during exercise. SETTING: Exercise stress test laboratory of a university hospital. PATIENTS AND DESIGN: Clinical and angiographic data were compared for 574 consecutive patients who developed ST segment depression during the active phase of an exercise test (group 1) and for 79 patients who developed ST segment depression only during the recovery phase of the exercise test (group 2). RESULTS: There were no differences between the two groups in major clinical features. Significant coronary artery stenoses were found in 488 group 1 patients (85%) and in 62 group 2 patients (78%, p = 0.14). Three vessel or left main disease was found in 166 (29%) group 1 and in 14 (18%) group 2 patients (p = 0.045). At a median follow up of 55.3 months of 321 group 1 and 54 group 2 patients, there were no significant differences in major cardiac events between the groups (univariate relative risk 0.81, 95% confidence interval 0.25 to 2.68, p = 0.72). CONCLUSION: The diagnostic and prognostic power of ST segment depression limited to the recovery phase of an exercise test is largely similar to that of ST segment depression induced during effort; thus, assessing ST segment depression during recovery can significantly improve the clinical information derived from exercise stress tests.