Sample volume positioning in colour-coded Doppler myocardial imaging: effect of systolic and diastolic tracking

To date, Doppler myocardial imaging (DMI) is no longer an intriguing new research tool only, but is rather on the verge of becoming a routinely used diagnostic method in adult and pediatric cardiology. Clinical studies have proven its diagnostic relevance for global left and right ventricular function. Concerns about reliability and reproducibility of DMI functional analysis, however, rely on lacking standards for the acquisition and analysis of DMI parameters. This study focuses on the effect of sample volume positioning during the cardiac cycle on the absolute myocardial velocities. Our hypothesis was that systolic sample volume placement leads to altered diastolic measurements, and diastolic placement vice versa to altered systolic measurements, when compared with continuous systolic and diastolic tracking. The effect of tracking on intra- and interobserver variability was a second endpoint of the study. Twenty healthy women underwent color-coded Doppler myocardial imaging. Clips of three heart cycles were stored in digital format for off-line analysis, administering sector angles of approximately 30 degrees and a mean frame rate of 280 frames per second. Using the Echopac software (GE, Germany), the sample volume was positioned immediately below the atrioventricular valvar annulus within the basal segments of the right and left ventricular free wall and the interventricular septum. Three conditions were investigated: conventional end-systolic or end-diastolic placement of the Doppler probe, or continuous tracking to the ideal position during systole or diastole. Descriptive statistics, intra and interobserver variabilities and Bland-Altman analyses were performed. Tracking revealed higher values of early diastolic myocardial velocities compared with measurements during systolic sample volume placement only, and higher systolic myocardial velocities, preejection acceleration and late diastolic myocardial velocities using diastolic sample volume placement. Inter and intraobserver reproducibility improved remarkably with the new procedure with the exception of isovolumic acceleration (IVA), which could not be reproduced satisfactorily at all. In summary, tracking is a promising method that helps to improve reproducibility of DMI-derived myocardial velocities. It helps to minimize the effect of changing myocardial velocities during the natural longitudinal cardiac movement, and should be considered as standard method during DMI.

Right heart failure due to an unroofed coronary sinus in an adult

An unroofed coronary sinus is a rare congenital malformation with a strong association to a persistent left vena cava superior. In most cases it occurs together with complex cardiac anomalies such as left isomerism. We report on a 72-year-old man with clinical signs of right heart failure caused by an isolated unroofed coronary sinus: The diagnosis was made by means of transesophageal echocardiography with contrast injection.

[Structural validity of the Short Form 36 (SF-36) in patients with rheumatic diseases]

BACKGROUND

Quality of life is gaining relevance as a criterion of success in therapeutic outcome studies. In order to record quality of life, disease-specific instruments are being used as well as generic instruments. Generic instruments offer the possibility to compare outcome among different indications; however for this it is necessary to prove the differential factorial validity of the instrument's structure.

AIM OF THE STUDY

Using structural equation modeling the SF-36 was administered to a sample of patients with rheumatic diseases. The sensitivity to change of the measure was calculated after six months. Furthermore, age- and sex-specific scale values were calculated and compared with norm data.

METHODS

SF-36 data of 436 patients as well as sex and age from two scientific rehabilitation research projects were pooled for this secondary analysis.

RESULTS

The structure of the questionnaire proves to be acceptable and comparable with international results. The confirmatory analysis supports the best fit for a model with crossloadings assuming correlated main dimensions. Sensitivity to change is low in general. The best effect size is found for the subscale pain. The comparison with norm data shows that patients are impaired particularly within their physical health (regarding the SF subscales) both at the beginning of the treatment and after six months. In all age groups men have better conditions than women.

CONCLUSIONS

The generic SF-36 show sufficient factorial validity. From this point of view there is no objection to using the SF-36 in patients with rheumatic diseases. Indeed the use of the SF summary scales as a representation of (uncorrelated) physical and mental health must be questioned critically.

Inhibitory and excitatory intracortical circuits across the human sleep-wake cycle using paired-pulse transcranial magnetic stimulation

Studies using single-pulse transcranial magnetic stimulation (TMS) have shown that excitability of the corticospinal system is systematically reduced in natural human sleep as compared to wakefulness with significant differences between sleep stages. However, the underlying excitatory and inhibitory interactions on the corticospinal system across the sleep-wake cycle are poorly understood. Here, we specifically asked whether in the motor cortex short intracortical inhibition (SICI) and facilitation (ICF) can be elicited at all in sleep using the paired-pulse TMS protocol, and if so, how SICI and ICF vary across sleep stages. We studied 28 healthy subjects at interstimulus intervals of 3 ms (SICI) and 10 ms (ICF), respectively. Magnetic stimulation was performed over the hand area of the motor cortex using a focal coil and evoked motor potentials were recorded from the contralateral first dorsal interosseus muscle (1DI). Relevant data was obtained from 13 subjects (NREM 2: n=7; NREM 3/4: n=7; REM: n=7). Results show that both SICI and ICF were present in NREM sleep. SICI was significantly enhanced in NREM 3/4 as compared to wakefulness and all other sleep stages whereas in NREM 2 neither SICI nor ICF differed from wakefulness. In REM sleep SICI was in the same range as in wakefulness, but ICF was entirely absent. These results in humans support the hypothesis derived from animal experiments which suggests that intracortical inhibitory mechanisms are involved in the control of neocortical pyramidal cells in NREM and REM sleep, but along different intraneuronal circuits. Further, our findings suggest that cortical mechanisms may additionally contribute to the inhibition of spinal motoneurones in REM sleep.

Präoperatives Mapping der Sprachareale mittels funktioneller Magnetresonanztomographie (fMRT) bei Patienten mit Hirntumoren: Ein Paradigmenvergleich

PURPOSE

Functional magnetic resonance imaging (fMRI) is a well-established, non-invasive method for pre-operative mapping of speech-eloquent areas. This investigation tests three simple paradigms to evaluate speech lateralisation and visualisation of speech-eloquent areas.

MATERIALS AND METHODS

14 healthy volunteers and 16 brain tumour patients were given three tasks: to enumerate months in the correct order (EM), to generate verbs fitting to a given noun (GV) and to generate words fitting to a given alphabetic character (GW). We used a blocked design with 80 measurements which consisted of 4 intervals of speech activation alternating with relaxation periods. The data were analysed on the basis of the general linear model using Brainvoyager(R). The activated clusters in the inferior frontal (Broca) and the posterior temporal (Wernicke) cortex were analysed and the laterality indices calculated.

RESULTS

In both groups the paradigms GV and GW activated the Broca's area very robustly. Visualisation of the Wernicke's area was best achieved by the paradigm GV. The paradigm EM did not reliably stimulate either the frontal or the temporal cortex. Frontal lateralisation was best determined by GW and GV, temporal lateralisation by GV.

CONCLUSION

The paradigms GV and GW visualise two essential aspects of speech processing: semantic word processing and word production. In a clinical setting with brain tumour patients, both, GV and GW can be used to visualise frontal and temporal speech areas, and to determine speech dominance.

Combined 123I-FP-CIT and 123I-IBZM SPECT for the diagnosis of parkinsonian syndromes: study on 72 patients

72 consecutive patients with suspected parkinsonian syndromes (PS) were studied by dopamine transporter (DAT) and D2 receptor SPECT in order to evaluate the accuracy of combined SPECT imaging. In the follow-up, the patients were diagnosed as having Parkinson's disease (PD, n = 25), dementia with Lewy bodies (DLB, n = 6), multiple system atrophy (MSA, n = 13), progressive supranuclear palsy (PSP, n = 8), corticobasal degeneration (CBD, n = 9), and essential tremor (ET, n = 11). Using the iteratively estimated optimal cutoffs, DAT was reduced in 57/61 PS patients, whereas all ET patients were identified as "normal". Reduced D2 receptor binding had 7/13 patients with MSA, 6/8 patients with PSP, 2/9 patients with CBD and no ET, PD or DLB patients. FP-CIT SPECT allows an accurate detection of nigrostriatal affection in neurodegenerative PS. IBZM SPECT is useful to approve the diagnosis of PSP and MSA although a normal finding cannot exclude an atypical PS. IBZM SPECT seems to be of restricted value in CBD.

Impaired left ventricular function after arterial switch operation: exclusion of significant coronary artery stenosis with an intravascular Doppler guidewire

Patients after arterial switch operation for transposition of the great arteries are at risk for coronary artery stenosis or obstruction due to intraoperative manipulation. This case describes an infant with impaired left ventricular function 8 months after arterial switch operation. A hemodynamically significant left coronary artery stenosis was excluded by determination of coronary flow reserve using an intravascular Doppler guidewire.

Myocardial perfusion and coronary flow reserve assessed by positron emission tomography in patients after Fontan-like operations

Ventricular dysfunction in patients after Fontan-like operations (FLOs) is a serious complication that might contribute to poor long-term results. Ischemic heart disease will have debilitating consequences on a Fontan heart. Ten patients (15.8 +/- 5.01 years) after FLO had transesophageal echocardiography and cardiac catheterization 9.3 +/- 4.2 years after surgery. Myocardial perfusion was assessed by NH3-positron emission tomography (rest/adenosine) and compared with that of 10 healthy adults (26.1 +/- 6.3 years). Ventricular function was normal in 4 and reduced in 6 patients; end systolic and end diastolic meridional wall stress was significantly elevated in the FLO group. Coronary angiography revealed no stenosis of the coronaries. Compared to normals, myocardial blood flow (MBF) at rest was higher in the FLO group (0.99 +/- 0.25 vs 0.77 +/- 0.17 ml/g/min, p <0.05), whereas MBF after vasodilatation (2.12 +/- 0.78 vs 3.10 +/- 0.85 ml/g/min, p <0.05) and coronary flow reserve (CFR) was reduced (2.5 +/- 0.88 vs 4.1 +/- 1.01, p <0.05), especially in those with impaired ventricular function. Coronary vascular resistance after vasodilatation was elevated in the FLO group (38.2 +/- 17.4 vs 24.5 +/- 8.3 mmHg/ml/g/min, p <0.05). Altered MBF, increased meridional wall stress, and impaired CFR are common findings in FLO. Attenuated CFR and reduced ventricular function are significantly correlated and may be risk factors for the long-term outcome.