Archivos del Instituto de Cardiologia de Mexico最新文献

Objectives: To evaluate the diagnostic utility of myocardial perfusion by SPECT and Gated-SPECT in the diagnosis of acute coronary syndrome in patients with precordial pain associated with normal or doubtful ischemic ECG within the first 6 hrs of the last episode of pain.

Methods: Sixty such patients who sought attention in the Emergency room were included. Myocardial perfusion SPECT and Gated-SPECT (GSPECT) was performed in all patients using two distinct protocols. All patients underwent resting and pharmacological stress test. In 30 cases coronary angiogram were performed.

Results: Resting myocardial perfusion was abnormal or positive in 25 patients (42%) and normal or negative in 35 patients (58%). In the latter group perfusion became abnormal in 15 patients (43%) under stress with dipyridamole, while it remained normal in 19 (54%). The last subgroup presented no coronary events during the 12 months following their hospital discharge. In the group of 25 patients with resting perfusion abnormalities acute myocardial infarction was diagnosed in 7 patients, ischemia in 12 and reverse-reversibility in 6. Myocardial perfusion scintigraphy showed in the resting phase a low sensitivity of 61% (95% CI 39-74%), and negative predictive value of 71% (95% CI, 58-82%). During the stress phase, the utility of the test increased significantly, with a sensitivity of 97% (95% CI, 83-99%), specificity of 79% (95% CI, 57-92%), positive predictive value of 87% (95% CI, 72-95%) and, most outstanding, a negative predictive value of 95% CI, 73-99%).

Conclusions: Myocardial perfusion studies have a sensitivity of 97% for identifying patients with acute coronary syndrome, with precordial pain and normal or doubtful ischemic ECG. For the intermediate or low risk patients with acute coronary syndrome the non-invasive diagnostic techniques of SPECT and GSPECT systems of evaluating myocardial perfusion achieve a high degree diagnostic accuracy, safety and reduces unnecessary admissions and costs.

Primary heart tumors are rare. The most common one is myxoma. It may synthetize IL-6 and frequently shown systemic clinical manifestations that confuse the diagnosis. Primary heart sarcomas are even more rare, as far as we know they have been not associated with systemic illnesses. We observed two cases with a presumptive diagnosis of systemic lupus erythematosus who were identified as primary sarcomatous heart neoplasms after surgical excision.

We present our early experience with the Gianturco-Grifka device for transcatheter closure of patent ductus arteriosus. Grifka occlusion was attempted in 13 patients (7 female, 6 male), median patient age was 6.5 years. Echocardiographic evaluation showed a mean ductal diameter of 5.47 +/- 1.09 mm, and the morphology was type C in 7 patients, type A in 5 and type E in 1 patient. The angiographic ductal morphology was 6 type A, 5 type C and 2 type E. Mean PDA diameter was 5.69 +/- 1.15 mm. Three patients had pulmonary hypertension. They were given supplemental oxygen (100%), decreasing their pulmonary pressures. A total of 13 devices were implanted, 5 of 7 mm and 8 of 9 mm. Twelve patients had complete ductal occlusion documented by aortic angiography (92%), one patient presented residual shunt (8%). Color echocardiography at 24 hrs documented complete occlusion in 12 cases. One device embolized to the descending aorta 2 hours after closure, and it was successfully retrieved in the catheterization lab. We conclude that the Gianturco-Grifka device is an appropriate alternative for transcatheter closure of the PDA. This technique can be performed in ductus arteriosus type C, D and E, with diameter < 9 mm. More clinical trials are needed to establish the long-term results of this technique.

Kearns-Sayre syndrome is a mitochondrial cytopathy characterized by chronic progressive external ophthalmoplegia, retinitis pigmentosa and heart block, the last of which determines the survival of these patients. The case of a 23 year old man with Kearns-Sayre syndrome, conduction disturbances and mitral valve prolapse is presented. The characteristics of this syndrome are described and the criteria for prophylactic installation of a pacemaker discussed.

Unlabelled: Myocardial perfusion SPECT has a high sensitivity for the diagnosis of myocardial ischemia. Adenosine has been recently used to induce myocardial ischemia in the United States and Europe. At the present time there is not published experience using adenosine in Mexico.

Method: We studied 22 patients with suspected myocardial ischemia. Coronary angiography was performed in 17 patients. We used a 8 mCi rest Tc-99m sestamibi followed by a 6 minute infusion of adenosine at a dose of 140 ug/kg/min; 24 mCi of Tc-99m were injected after the third minute of adenosine infusion. Patients returned 2 or 3 days later for a new stress study using physical stress or dipiridamole and the images were read using a 20 segments analysis and each segment was scored using a 5 points scale (0 = normal to 4 = absent uptake). The results were then compared with the adenosine images.

Results: The segmental score agreement between adenosine and physical or dipyridamole stress were good with 90% exact correlation. The side effects experienced by patients who received dipyridamole and adenosine were similar.

Conclusion: Adenosine is a good alternative to induce myocardial ischemia. It showed a good correlation with physical or dipyridamole stress test.

The behavior of temporal and spectral parameters of the heart rate variability was determined during 5 different maneuvers in order to characterize the level of sympathetic-vagal activity. The discriminating capacity of two spectral parameter estimation schemes were compared, and the respiratory influence was evaluated. One hundred and ten records of instantaneous heart rate and respiratory amplitude were analyzed, both in temporal and spectral perspectives. The records were obtained from 22 healthy subjects, under a five-stage protocol: supine, controlled breathing, standing, exercise, and recovery. A discriminating and characteristic behavior was found among the maneuvers, specifically for the dispersion parameters, low and intermediate partial components. The two integration-normalization procedures used in the estimation of the spectral components showed similarities, producing a functional interpretation independent of the selected procedure. The division of the low frequency component in two separate bands, allowed an improved discriminating capacity. The respiration had an important influence in the controlled breathing maneuver while being lower in the rest of the stages. In conclusion, the maneuvers determined a typical behavior of the dispersion and spectral parameters (low and intermediate partial components) of the heart rate variability, showing adequate distinctive levels in the sympathetic-vagal activity for each maneuver.

Unlabelled: We review our experience and also evaluate the clinical and angiographic results of octagenarians patients subjected to percutaneous transluminal angioplasty and endovascular prosthesis (stents). In the period between february 1995 and august 1998, 532 procedures were performed in 400 patients, we describe a subgroup of 51 patients, who rejected surgical treatment or were considered non appropriate candidates for this therapeutic approach. Ages ranged 71 a 85 years mean (74.09 +/- 3.1). Sex: 37 male and 14 female, their clinical presentation was severe angina according to Canadian Society of Cardiology (CSC) in 64%. In 64% previous myocardial infarction and multivessel disease in 58.8%. The mean percentage of coronary obstruction was 90 +/- 9.2 and ejection fraction 51.6 +/- 8.8, the immediate angiographic success was 88.3% six patient (12%) died during 36 to 72 hours post-procedure from different causes. The follow-up period was 3 to 48 months, but had angiographic control just eighteen patients (35%). Eighteen cases were lost to follow-up for different reasons. Two patients died of non cardiac causes.

Conclusions: Stent implantation has an angiographic and clinical success with low complications profile. It is a therapeutic option in the management of advanced coronary artery disease in this frail group.