Athanassios Kranidis

Coronary microcirculation evaluation with transesophageal echocardiography Doppler in type II diabetics

Evaluation of coronary microvascular function can be obtained through coronary flow reserve measurements. The aim of this study was to evaluate the coronary microvascular function by using transesophageal-Doppler echocardiographic assessment of coronary flow reserve. The study included 32 normotensive patients with type II diabetes mellitus (group A) of short duration (6.1+/-3.8 years) aged 55.4+/-9.4 years and 14 healthy volunteers matched for age, gender and BMI (group B). No patients had clinical evidence of coronary artery disease and all of them produced a negative recent stress ECG test. Excluded from the study were patients with anemia, left ventricular hypertrophy, arrhythmia, congenital, or acquired structural heart disease. All subjects underwent transesophageal-Doppler echocardiography. Satisfactory coronary blood flow velocity recordings could be obtained from the initial segment of the left anterior descending coronary artery in healthy volunteers and in 27 patients at baseline and 2 min after dipyridamole infusion (0.56 mg/kg, for 4 min). In the remaining 5 patients no satisfactory recordings were available. The indexes of coronary flow reserve, i.e. the ratios of dipyridamole over basal maximum and mean diastolic velocities were calculated. Dipyridamole/rest maximal coronary reserve (Table 3) was 1.946+/-0.743, while this ratio for the mean diastolic velocity was 1.969+/-0.805 in group A. The respective values for group B, were 2.811+/-0.345 (P=0.000 vs. group A) and 2.914+/-0.303 (P=0.000 vs. group A). Thus, the increase in coronary flow reserve although present in both groups, it was more impressive in the normal group. Multiple regression logistic analysis of: age, sex, smoking, glucosylated hemoglobin, duration of diabetes and type of therapy, did not show any correlation of these parameters with the above ratios. This study shows that coronary flow reserve, as measured with transesophageal echocardiography-Doppler, is severely impaired in normotensive patients with type II diabetes, with relatively short duration of the disease.

Functional and prognostic significance of silent ischemia during dobutamine stress echocardiography in the elderly.

BackgroundThe functional and prognostic significance of silent ischemia relative to symptomatic ischemia during non‐invasive testing remains controversial. DesignThe aim of this prospective study was to assess whether the presence of dobutamine‐induced silent ischemia was associated with the amount of myocardial ischemic burden and to determine the prognostic significance of painless ischemia in elderly people with stable coronary artery disease. MethodsA cohort of 289 patients ≥70 years of age with positive dobutamine stress echocardiography result and significant coronary artery disease proven by coronary arteriography, were followed up during a 35 ± 13 month period for the development of cardiac events. ResultsThe prevalence of silent ischemia during dobutamine infusion was 63%. Patients with painful ischemia were more likely to have lower peak heart rate (P  < 0.01) and showed ST segment depression more frequently during the dobutamine stress test than did patients with painless ischemia (52 versus 31%, P  < 0.05). There was no significant difference between the patients with and without angina according to wall motion score index at rest (1.35 ± 0.29 versus 1.32 ± 0.37) and at peak stress (1.61 ± 0.35 versus 1.58 ± 0.44), stress–rest wall motion index difference (0.27 ± 0.09 versus 0.25 ± 0.08), the presence of dyskinesia at peak stress (36 versus 31%), the number of segments with regional ≥2 point change from rest to peak stress (38 versus 29%) and the decrease of left ventricular end systolic volume at peak stress (89 versus 86%). During the follow‐up period a total of 269 patients developed 153 (57%) cardiac events: 15 cardiac deaths, 19 non‐fatal myocardial infarctions, 119 episodes of unstable angina. No significant difference in cardiac mortality and in total cardiac event rate was observed between patients with or without angina (6 versus 5% and 60 versus 55%, respectively). ConclusionsOur data demonstrate that the magnitude of myocardial dysfunction assessed by dobutamine stress echocardiography is comparable in elderly patients with or without anginal chest pain. The presence of painful ischemia is not accompanied by an increased risk for subsequent cardiac events in this cohort of patients.

Mitral Regurgitation Protects from Left Atrial Thrombogenesis in Patients with Mitral Valve Disease and Atrial Fibrillation

The aim of this study was to test the hypothesis that mitral regurgitation (MR) has a protective effect on the development of left atrial thrombus (LAT) in patients with rheumatic heart disease and atrial fibrillation (AF). The study population consisted of 48 anticoagulated patients (mean age = 57.1 ± 10 years). Predominant mitral stenosis (MS) was present in 14 patients, predominant MR in 14, and a mechanical valve in 20. All patients underwent detailed transesophageal echocardiography. Severity of MR was based on measurements of the MR jet by color flow mapping. Patients were divided into two groups: (a) those with MR ≥ 3 + (n =12, 25%), and (b) those without significant MR (n = 36, 75%). A LAT was found in six patients (12.5%), who also had spontaneous echo contrast (SEC), while another group of 30 patients (62.5%) had SEC only. LAT and/or SEC were present in 2/12 patients (16.6%) with significant MR versus 34/36 patients (94.4%) without significant MR (P < 0.001). In addition to the absence of significant MR, left atrial diameter (LAD) > 60 mm, and severity of MS were also related to the presence of thrombus and/or SEC. Significant MR had a protective effect against thromboembolism, although this effect was abolished if LAD > 60 mm was present. In conclusion, in patients with mitral valve disease and AF, significant MR protects against LAT formation and systemic embolization. This protective effect was lost when LAD was > 60 mm.

Echocardiographic detection of the extent of coronary artery disease in the elderly using dobutamine and adenosine infusion.

Background The high prevalence of asymptomatic multivessel disease in the elderly and the fact that most of them can not carry out an exercise stress testing renders the application of other stress modalities necessary. The aim of this study is to compare the diagnostic value of dobutamine and adenosine stress echocardiography and their accuracy in determining the extent of coronary artery disease in elderly people.Methods Dobutamine and adenosine stress echocardiography were performed in 128 consecutive patients ≥ 70 years-of-age with known or suspected coronary artery disease. All patients underwent coronary angiography within 2 weeks of the stress tests.Results The presence of any echocardiographic abnormality on dobutamine (odds ratio 30.8) and adenosine (odds ratio 18.1) test, the need for cessation of dobutamine test and the ST depression during dobutamine infusion, were independent predictors of significant coronary artery disease. Both tests proved more sensitive for detecting multivessel disease (89% for dobutamine, 74% for adenosine test), than one-vessel disease (74 and 39%, respectively). This difference was statistically significant only for the adenosine echocardiography test (P= 0.008). In patients with localized resting wall motion abnormalities, the accuracy of dobutamine test to predict a remotely diseased vessel (70%), was statistically superior to the accuracy of adenosine test (57%, P= 0.008). Patients with multivessel disease showed delayed resolution of test-induced wall motion abnormalities, during the recovery period after both tests, compared with those who suffered from one-vessel disease.Conclusions Dobutamine echocardiography was more sensitive and accurate than adenosine echocardiography in detecting and determining the extent and the severity of coronary artery disease in the elderly. A positive adenosine echocardiography result reflected the presence of advanced coronary artery disease. The two tests, combined with clinical data, could classify the elderly into low- and high-risk subgroups for ischemic heart disease.

Posterior Right Diagonal Artery An Angiographic Study

The purpose of this prospectively performed study was the angiographic visualization of the posterior right diagonal artery (PRDA) and its differentiation from the epicardial branches of the right coronary artery (RCA), that is, the right marginal artery and the posterior descending artery (PDA). The authors prospectively studied the angiographic findings of 607 patients who underwent coronary angiography. The incidence of the angiographically demonstrated PRDA and its distinction from other epicardial branches arising from the distal third of the RCA was the main point of interest. Two types of PDA in those cases where PRDA was present were also demonstrated. Of the patients examined, 535 had dominant right coronary circulation, 59 had left dominant coronary circulation, and 13 had balanced coronary circulation. PRDA was present in 81 patients with right dominant coronary circulation (15.1%), in 2 patients with balanced coronary circulation (15.4%), and in none with left dominant coronary circulation. PRDA was revealed in 48 (40%) of 120 patients with a short PDA and in only 33 (8%) of 415 patients having long PDA. It is imperative to search always for the PRDA, when one is studying coronary arte riographies, bearing in mind that this artery may perfuse the inferior part of the posterior interventricular septum and the adjoining area, depending on the type of PDA.

Non-invasive evaluation of coronary reserve Assessment of coronary reserve in patients with coronary artery disease by transesophageal-Doppler echocardiography

We assessed coronary flow reserve using transesophageal Doppler echocardiography in patients with coronary artery disease. The study included 33 coronary artery disease patients who were undergoing coronary arteriography. The blood flow velocities of the left anterior descending artery before and after intravenous infusion (0.56 mg/min for 4 min) of dipyridamole were recorded using transesophageal Doppler echocardiography. Fourteen normal healthy individuals, matched for age, served as a control group. The index of coronary flow reserve, i.e. the ratio of dipyridamole to baseline maximum diastolic velocity, was calculated. Maximal coronary flow reserve in coronary artery disease patients was significantly lower than in the control group (1.4+/-0.2 vs. 2.8+/-0.3, P<0.001). The coronary artery disease patients were classified into three groups: Group A included 10 patients with <50% left anterior descending artery stenosis; Group B included seven patients with 50-69% left anterior descending artery stenosis; 16 patients with >70% left anterior descending artery stenosis constituted Group C. The maximum coronary flow reserve was significantly different for A vs. B and A vs. C. (A, 1.77+/-0.18; B, 1.51+/-0.1; C, 1.28+/-0.24). A strong and significant correlation was found between the maximum coronary flow reserve and the degree of proximal left anterior descending artery stenosis (r=0.78, P<0.001). Coronary artery disease patients without left anterior descending artery stenosis on the arteriogram exhibited lower maximum coronary flow reserve compared to the control subjects (1.78+/-0.19 vs. 2.8+/-0.3, P=0.000).

Persistent left superior vena cava in Holt–Oram syndrome

We thank Dr Cheng for his comments on our with a cycle length of 545 ms caused a 2:1 distal article [1]. The Holt–Oram syndrome is characterized block. These abnormalities have been described in by skeletal abnormalities and congenital cardiac patients with Holt–Oram syndrome. However, and in defects. In a recent article, Basson et al. [2] reported patients with persistent left superior vena cava, it has concordance of Holt–Oram phenotypes with specific been described as sinus node disease and disturbances mutations of the TBX5 gene. Defects predicted to of atrioventricular conduction, as in our case [5,6]. create null alleles caused composite cardiac defects These conduction disturbances have been attributed and severe skeletal malformations. In contrast, misto a probable compression of the atrioventricular ense mutations caused (a) phenotypes with severe conduction system by the enlarged coronary sinus cardiac abnormalities and minor skeletal malforma[7]. tions or (b) phenotypes with extensive upper limb From the existing data we cannot conclude if the malformations but less significant cardiac defects. existence of PLSVC in our patient with Holt–Oram Thus, involvement of heart or limb occurs as the Syndrome is an incidental finding, but it was the only consequence of a specific mutation of a gene. cardiac abnormality. In both cases with Holt–Oram syndrome and Another point that should be taken into considerapersistent left superior vena cava (PLSVC), described tion in patients with PLSVC, especially if upper limb by Dr Cheng [3,4], another cardiac ‘defect’ was also abnormalities coexist, is that difficulties may arise present (atrial septal defect and increased right venduring the implantation of a permanent pacemaker. In tricular trabeculations, respectively). the case described, we confirmed the difficulties in In the patient with Holt–Oram syndrome, we have introducing the pacing lead via the persistent left described PLSVC was the only cardiac defect [1]. superior vena cava and in fixating the electrode PLSVC is the most common congenital anomaly of because of its abnormal route through the PLSVC the venous system and there is the possibility that in before arriving in the right ventricle. the described patient, PLSVC was an incidental The need for an active fixation lead in pacing finding in a patient with a mutation that causes only patients with a persistent left superior vena cava has skeletal anomalies. been stressed in the literature [6]. What has not been However, our patient had also history of syncope described is the extreme difficulty involved in removand abnormalities in the conduction system. The ing the pacing lead through this anomalous vessel, electrophysiological study showed abnormal insuch as we encountered in our case. This was traventricular conduction and rapid right atrial pacing probably due to the existence of a valve in the PLSVC, or to stenosis at the point where it drained into the coronary sinus. The difficulties in removing *Corresponding author. Tel.: 130-1-8048-427; fax: 131-1-804-8427. E-mail address: geros@compulink.gr (G. Filippatos). the conventional lead had a negative effect on the